Zoom lens system

ABSTRACT

A zoom lens system includes a negative first lens group, a positive second lens group, a negative third lens group and a positive fourth lens group, in that order from the object side. Upon zooming from a short focal length extremity to a long focal length extremity, at least the first lens group, the second lens group and the fourth lens group are moved in the optical axis direction of the zoom lens. The third lens group includes a negative first sub-lens group and a negative second sub-lens group, in that order from the object side, the second sub-lens group is provided with a negative single lens element and a positive single lens element, and an air lens is formed between the negative single lens element and the positive single lens element.

CROSS REFERENCE TO RELATED APPLICATIONS

This is a divisional application of U.S. patent application Ser. No.14/524,472, filed Oct. 27, 2014, which claims the benefit of JapanesePatent Application No. 2013-227785, filed Nov. 1, 2013, and JapaneseApplication No. 2013-227784 filed Nov. 1, 2013. The entire disclosure ofeach of the above-identified applications, including the specification,drawings, and claims, is incorporated herein by reference in itsentirety.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates to a zoom lens system, and in particular,relates to a wide-angle zoom lens system that is favorable for use in asingle-lens reflex camera. In addition, the present invention relates toan intra-lens image-stabilizing zoom optical system in which part of thelens system thereof can be decentered in order to correct image-blurcaused by vibrations/hand-shake, etc.

2. Description of Related Art

Since it is relatively easy for a so-called “negative-lead zoom lenssystem”, in which a lens group having a negative refractive power isprovided closest to the object side, to obtain a wide angle-of-view anda long backfocus relative to the focal length, negative-lead zoom lenssystems are often utilized in wide-angle zoom lens systems for use in asingle-lens reflex camera.

A number of negative-lead zoom lens systems have been proposed in whichan image-stabilizing function (image-shake correcting function) isinstalled, which corrects deviations in the imaging position caused byvibrations/hand-shake, etc., by decentering part of the lens systemthereof in a direction orthogonal to the optical axis direction (referto Patent Literature 1 through 4 indicated below).

In such intra-lens image-stabilizing zoom optical systems, aberrationssuch as decentration coma, in a state where a image-stabilizing lensgroup is decentered, and image plane tilt, etc., are required to befavorably corrected, and aberration fluctuations occurring during animage-stabilizing drive operation are also required to be reduced.

In regard to such requirements, in order to apply the image-stabilizingzoom lens systems disclosed in Patent Literature 1 through 4 to ahighly-pixelized digital camera, etc., which requires a relatively highoptical quality, the correction of aberrations during animage-stabilizing drive operation (during decentering of animage-stabilizing lens group) and the optical quality are insufficient.

In order to improve the optical quality of the zoom lens system duringan image-stabilizing drive operation, it is effective to increase thefreedom in design of the image-stabilizing lens group and to reduce theoccurrence of aberrations within the image-stabilizing lens group byincreasing the number of lens elements thereof or by utilizing at leastone aspherical surface therein.

However, if the number of lens elements of the image-stabilizing lensgroup are increased too much, the burden on the drive mechanism for theimage-stabilizing lens group increases, and also causes enlargement ofthe entire zoom lens system (and also the entire apparatus whichincludes the drive mechanism of the image-stabilizing lens group).Furthermore, an increase in the number of lens elements in theimage-stabilizing lens group and the use of lens elements having atleast one aspherical surface become a cause for increasing themanufacturing costs.

On the other hand, such negative-lead wide-angle zoom lens systems for asingle-lens reflex camera are known to be configured of a negative firstlens group, a positive second lens group, a negative third lens groupand a positive fourth lens group, in that order from the object side(refer to Patent Literature 5 through 10 indicated below).

Generally, in a wide-angle zoom lens system, since abaxial aberrationssuch as distortion, field curvature, astigmatism, and lateral chromaticaberration, etc., occur together with a zooming operation or a focusingoperation being carried out, it is difficult to obtain a high opticalquality over the entire focal length range and over the entirephotographing distance range.

In regard to this matter, the zoom lens systems in Patent Literature 5through 10 are no exception; in order to apply the zoom lens systems ofPatent Literature 5 through 10 to a highly-pixelized digital camera,etc., which requires a relatively high optical quality, the opticalquality thereof is insufficient, and aberration fluctuations, whichaccompany a change in focal length or photographing distance, arerequired to be favorably corrected.

PATENT LITERATURE

-   [Patent Literature 1] Japanese Unexamined Patent Publication No.    H07-152002-   [Patent Literature 2] Japanese Unexamined Patent Publication No.    2004-61910-   [Patent Literature 3] Japanese Unexamined Patent Publication No.    2010-170061-   [Patent Literature 4] Japanese Unexamined Patent Publication No.    2010-217535-   [Patent Literature 5] Japanese Unexamined Patent Publication No.    2002-287031-   [Patent Literature 6] Japanese Unexamined Patent Publication No.    2008-145967-   [Patent Literature 7] Japanese Unexamined Patent Publication No.    2008-281917-   [Patent Literature 8] Japanese Unexamined Patent Publication No.    2011-145518-   [Patent Literature 9] Japanese Unexamined Patent Publication No.    2012-63568-   [Patent Literature 10] Japanese Unexamined Patent Publication No.    2012-68303

SUMMARY OF THE INVENTION

The present invention has been devised in view of the above-mentionedproblems, and provides a zoom lens system which, in particular, achievesa superior optical quality by favorably correcting aberrations whichoccur during an image-stabilizing drive operation (when decentering theimage-stabilizing lens group), while reducing the burden on the drivemechanism of the image-stabilizing lens group, miniaturizing the entirezoom lens system (and also the entire apparatus including theimage-stabilizing lens group), and reducing the manufacturing cost.

Furthermore, in a wide-angle zoom lens system for use in a single-reflexcamera in particular, the present invention also obtains a high opticalquality over the entire focal length range and over the entirephotographing distance range while suppressing abaxial aberrations suchas distortion, field curvature, astigmatism, and lateral chromaticaberration, etc.

According to an aspect of the present invention, a zoom lens system isprovided, including a negative first lens group, a positive second lensgroup, a negative third lens group and a positive fourth lens group, inthat order from the object side. Upon zooming from the short focallength extremity to the long focal length extremity, at least the firstlens group, the second lens group and the fourth lens group are moved inthe optical axis direction thereof. The third lens group includes anegative first sub-lens group and a negative second sub-lens group, inthat order from the object side. The second sub-lens group is providedwith a negative single lens element and a positive single lens element,wherein an air lens is formed between the negative single lens elementand the positive single lens element.

It is desirable for the second sub-lens group to include a negativesingle lens element having a concave surface on the image side, and apositive single lens element having convex surface on the object side,in that order from the object side, wherein a meniscus shaped air lenshaving a convex surface on the object side is formed between thenegative single lens element and the positive single lens element.

It is desirable for the following condition (1) to be satisfied:

0.1<Ri/Ro<1.1  (1),

wherein Ri designates the radius of curvature of the surface on theimage side of the air lens provided within the second sub-lens group,and Ro designates the radius of curvature of the surface on the objectside of the air lens provided within the second sub-lens group.

It is desirable for the focal length of the air lens provided within thesecond sub-lens group to have a positive value.

It is desirable for the following condition (2) is satisfied:

—0.7<(R3ao+R3ai)/(R3ao−R3ai)<0.3  (2),

wherein R3ao designates the radius of curvature of the surface on theobject side of the first sub-lens group, and R3ai designates the radiusof curvature of the surface on the image side of the first sub-lensgroup.

It is desirable for the following condition (3) to be satisfied:

−1.1<(R3ai+R3bo)/(R3ai−R3bo)<0.7  (3),

wherein R3ai designates the radius of curvature of the surface on theimage side of the first sub-lens group, and R3bo designates the radiusof curvature of the surface on the object side of the second sub-lensgroup.

It is desirable for the following conditions (4) and (5) to besatisfied:

−0.7<(1−m3bS)·m4S<−0.2  (4),

and

−0.8<(1−m3bL)·m4L<−0.3  (5),

wherein m3bS designates the lateral magnification of the second sub-lensgroup when focusing on an object at infinity at the short focal lengthextremity, m4S designates the lateral magnification of the fourth lensgroup when focusing on an object at infinity at the short focal lengthextremity, m3bL designates the lateral magnification of the secondsub-lens group when focusing on an object at infinity at the long focallength extremity, and m4L designates the lateral magnification of thefourth lens group when focusing on an object at infinity at the longfocal length extremity.

Upon zooming from the short focal length extremity to the long focallength extremity, the third lens group can remain stationary withrespect to the optical axis direction thereof. Alternatively, uponzooming from the short focal length extremity to the long focal lengthextremity, the third lens group can move in the optical axis directionthereof.

In an embodiment, a zoom lens system is provided, including a negativefirst lens group, a positive second lens group, a negative third lensgroup and a positive fourth lens group, in that order from the objectside. Upon zooming from the short focal length extremity to the longfocal length extremity, at least the first lens group, the second lensgroup and the fourth lens group move in the optical axis directionthereof, wherein the following condition (6) is satisfied:

1.35<ΔX4/ΔX2<2.80  (6),

wherein ΔX2 designates an amount of movement of the second lens group inthe optical axis direction thereof when zooming from the short focallength extremity to the long focal length extremity, and ΔX4 designatesan amount of movement of the fourth lens group in the optical axisdirection thereof when zooming from the short focal length extremity tothe long focal length extremity.

In condition (6), ΔX2 and ΔX4 have no concept of a positive or anegative movement amount, in other words, ΔX2 and ΔX4 designate absolutevalues of movement amounts toward the object side or toward the imageside. Accordingly, ΔX2 and ΔX4 and also ΔX4/ΔX2 never take a negativevalue but are always a positive value, not only in the case where thesecond lens group and the fourth lens group are both moved toward theobject side or are both moved toward the image side, but also in thecase where one of the second lens group and the fourth lens group movestoward the object side and the other thereof moves toward the imageside.

It is desirable for, upon zooming from the short focal length extremityto the long focal length extremity, the third lens group to remainstationary with respect to the optical axis direction thereof.

It is desirable for the following condition (7) to be satisfied:

−1.95<f2/f1<−1.55  (7),

wherein f1 designates the focal length of the first lens group, and f2designates the focal length of the second lens group.

It is desirable for the following condition (8) to be satisfied:

2.25<f3/f1<3.50  (8),

wherein f1 designates the focal length of the first lens group, and f3designates the focal length of the third lens group.

It is desirable for the following condition (9) to be satisfied:

−3.00<f4/f1<−2.05  (9),

wherein f1 designates the focal length of the first lens group, and f4designates the focal length of the fourth lens group.

It is desirable for the second lens group to include a positive firstsub-lens group and a positive second sub-lens group, in that order fromthe object side. The first sub-lens group serves as a focusing lensgroup which is moved in the optical axis direction thereof during afocusing operation. The following conditions (10) and (11) aresatisfied:

−1.2<(1−m2aS ²)mRS ²<−0.8  (10),

and

−2.7<(1−m2aL ²)mRL ²<−1.7  (11),

wherein m2aS designates the lateral magnification of the first sub-lensgroup when focusing on an object at infinity at the short focal lengthextremity, mRS designates the combined lateral magnification of thesecond sub-lens group, the third lens group and the fourth lens group,when focusing on an object at infinity at the short focal lengthextremity, m2aL designates the lateral magnification of the firstsub-lens group when focusing on an object at infinity at the long focallength extremity, and mRL designates the combined lateral magnificationof the second sub-lens group, the third lens group and the fourth lensgroup, when focusing on an object at infinity at the long focal lengthextremity.

It is desirable for the first sub-lens group to include a positive lenselement having a convex surface on the object side, and a cemented lenshaving a negative lens element having a convex surface on the objectside and a positive lens element, in that order from the object side.

It is desirable for the fourth lens group to include a positive thirdsub-lens group and a negative fourth sub-lens group, in that order fromthe object side. The third sub-lens group is formed as a cemented lenswhich is provided with a positive lens element having a convex surfaceon the object side, a negative lens element and a biconvex positive lenselement, in that order from the object side. The following condition(12) is satisfied:

15<νdp−νdn<25  (12),

wherein νdp designates an average value of the Abbe number at the d-lineof the positive lens elements provided in the third sub-lens group, andνdn designates the Abbe number at the d-line of the negative lenselement provided in the third sub-lens group.

It is desirable for the zoom lens system of the present invention tosatisfy the following conditions (13) and (14):

5<m2S/m4S<35  (13),

and

3.5<m2L/m4L<7.5  (14),

wherein

m2S designates the lateral magnification of the second lens group whenfocusing on an object at infinity at the short focal length extremity,m4S designates the lateral magnification of the fourth lens group whenfocusing on an object at infinity at the short focal length extremity,m2L designates the lateral magnification of the second lens group whenfocusing on an object at infinity at the long focal length extremity,and m4L designates the lateral magnification of the fourth lens groupwhen focusing on an object at infinity at the long focal lengthextremity.

It is desirable for the first lens group, of the zoom lens system of thepresent invention, to include a negative lens element having a convexsurface on the object side, a negative lens element having a convexsurface on the object side, a biconcave negative lens element, and apositive lens element having a convex surface on the object side, inthat order from the object side, and to satisfy the following condition(15):

0.56<θgF<0.60  (15),

wherein

θgF designates the partial dispersion ratio at the g-line and at theF-line of the positive lens element that is provided closest to theimage side within the first lens group.

According to the present invention, a zoom lens system is providedwhich, in particular, achieves a superior optical quality by favorablycorrecting aberrations which occur during an image-stabilizing driveoperation (when decentering the image-stabilizing lens group), whilereducing the burden on the drive mechanism of the image-stabilizing lensgroup, miniaturizing the entire zoom lens system (and also the entireapparatus including the image-stabilizing lens group), and reducing themanufacturing cost.

Furthermore, according to the present invention, in a wide-angle zoomlens system for use in a single-reflex camera in particular, a highoptical quality is achieved over the entire focal length range and overthe entire photographing distance range while suppressing abaxialaberrations such as distortion, field curvature, astigmatism, andlateral chromatic aberration, etc.

The present disclosure relates to subject matter contained in JapanesePatent Application Nos. 2013-227784 and 2013-227785 (both filed on Nov.1, 2013) which are expressly incorporated herein in their entireties.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be discussed below in detail with referenceto the accompanying drawings, in which:

FIG. 1 shows a lens arrangement of a first numerical embodiment of azoom lens system, according to the present invention, at the short focallength extremity when focused on an object at infinity;

FIGS. 2A, 2B, 2C and 2D show various aberrations that occurred in thelens arrangement shown in FIG. 1, at the short focal length extremitywhen focused on an object at infinity;

FIGS. 3A, 3B and 3C show lateral aberrations that occurred in the lensarrangement shown in FIG. 1, at the short focal length extremity whenfocused on an object at infinity;

FIGS. 4A, 4B, 4C and 4D show various aberrations that occurred in thelens arrangement shown in FIG. 1, at an intermediate focal length whenfocused on an object at infinity;

FIGS. 5A, 5B and 5C show lateral aberrations that occurred in the lensarrangement shown in FIG. 1, at an intermediate focal length whenfocused on an object at infinity;

FIGS. 6A, 6B, 6C and 6D show various aberrations that occurred in thelens arrangement shown in FIG. 1, at the long focal length extremitywhen focused on an object at infinity;

FIGS. 7A, 7B and 7C show lateral aberrations that occurred in the lensarrangement shown in FIG. 1, at the long focal length extremity whenfocused on an object at infinity;

FIGS. 8A, 8B and 8C show lateral aberrations that occurred in the lensarrangement shown in FIG. 1 when the image-stabilizing lens group isdecentered, at the short focal length extremity when focused on anobject at infinity;

FIGS. 9A, 9B and 9C show lateral aberrations that occurred in the lensarrangement shown in FIG. 1 when the image-stabilizing lens group isdecentered, at an intermediate focal length when focused on an object atinfinity;

FIGS. 10A, 10B and 10C show lateral aberrations that occurred in thelens arrangement shown in FIG. 1 when the image-stabilizing lens groupis decentered, at the long focal length extremity when focused on anobject at infinity;

FIG. 11 shows a lens arrangement of a second numerical embodiment of azoom lens system, according to the present invention, at the short focallength extremity when focused on an object at infinity;

FIGS. 12A, 12B, 12C and 12D show various aberrations that occurred inthe lens arrangement shown in FIG. 11, at the short focal lengthextremity when focused on an object at infinity;

FIGS. 13A, 13B and 13C show lateral aberrations that occurred in thelens arrangement shown in FIG. 11, at the short focal length extremitywhen focused on an object at infinity;

FIGS. 14A, 14B, 14C and 14D show various aberrations that occurred inthe lens arrangement shown in FIG. 11, at an intermediate focal lengthwhen focused on an object at infinity;

FIGS. 15A, 15B and 15C show lateral aberrations that occurred in thelens arrangement shown in FIG. 11, at an intermediate focal length whenfocused on an object at infinity;

FIGS. 16A, 16B, 16C and 16D show various aberrations that occurred inthe lens arrangement shown in FIG. 11, at the long focal lengthextremity when focused on an object at infinity;

FIGS. 17A, 17B and 17C show lateral aberrations that occurred in thelens arrangement shown in FIG. 11, at the long focal length extremitywhen focused on an object at infinity;

FIGS. 18A, 18B and 18C show lateral aberrations that occurred in thelens arrangement shown in FIG. 11 when the image-stabilizing lens groupis decentered, at the short focal length extremity when focused on anobject at infinity;

FIGS. 19A, 19B and 19C show lateral aberrations that occurred in thelens arrangement shown in FIG. 11 when the image-stabilizing lens groupis decentered, at an intermediate focal length when focused on an objectat infinity;

FIGS. 20A, 20B and 20C show lateral aberrations that occurred in thelens arrangement shown in FIG. 11 when the image-stabilizing lens groupis decentered, at the long focal length extremity when focused on anobject at infinity;

FIG. 21 shows a lens arrangement of a third numerical embodiment of azoom lens system, according to the present invention, at the short focallength extremity when focused on an object at infinity;

FIGS. 22A, 22B, 22C and 22D show various aberrations that occurred inthe lens arrangement shown in FIG. 21, at the short focal lengthextremity when focused on an object at infinity;

FIGS. 23A, 23B and 23C show lateral aberrations that occurred in thelens arrangement shown in FIG. 21, at the short focal length extremitywhen focused on an object at infinity;

FIGS. 24A, 24B, 24C and 24D show various aberrations that occurred inthe lens arrangement shown in FIG. 21, at an intermediate focal lengthwhen focused on an object at infinity;

FIGS. 25A, 25B and 25C show lateral aberrations that occurred in thelens arrangement shown in FIG. 21, at an intermediate focal length whenfocused on an object at infinity;

FIGS. 26A, 26B, 26C and 26D show various aberrations that occurred inthe lens arrangement shown in FIG. 21, at the long focal lengthextremity when focused on an object at infinity;

FIGS. 27A, 27B and 27C show lateral aberrations that occurred in thelens arrangement shown in FIG. 21, at the long focal length extremitywhen focused on an object at infinity;

FIGS. 28A, 28B and 28C show lateral aberrations that occurred in thelens arrangement shown in FIG. 21 when the image-stabilizing lens groupis decentered, at the short focal length extremity when focused on anobject at infinity;

FIGS. 29A, 29B and 29C show lateral aberrations that occurred in thelens arrangement shown in FIG. 21 when the image-stabilizing lens groupis decentered, at an intermediate focal length when focused on an objectat infinity;

FIGS. 30A, 30B and 30C show lateral aberrations that occurred in thelens arrangement shown in FIG. 21 when the image-stabilizing lens groupis decentered, at the long focal length extremity when focused on anobject at infinity;

FIG. 31 shows a lens arrangement of a fourth numerical embodiment of azoom lens system, according to the present invention, at the short focallength extremity when focused on an object at infinity;

FIGS. 32A, 32B, 32C and 32D show various aberrations that occurred inthe lens arrangement shown in FIG. 31, at the short focal lengthextremity when focused on an object at infinity;

FIGS. 33A, 33B and 33C show lateral aberrations that occurred in thelens arrangement shown in FIG. 31, at the short focal length extremitywhen focused on an object at infinity;

FIGS. 34A, 34B, 34C and 34D show various aberrations that occurred inthe lens arrangement shown in FIG. 31, at an intermediate focal lengthwhen focused on an object at infinity;

FIGS. 35A, 35B and 35C show lateral aberrations that occurred in thelens arrangement shown in FIG. 31, at an intermediate focal length whenfocused on an object at infinity;

FIGS. 36A, 36B, 36C and 36D show various aberrations that occurred inthe lens arrangement shown in FIG. 31, at the long focal lengthextremity when focused on an object at infinity;

FIGS. 37A, 37B and 37C show lateral aberrations that occurred in thelens arrangement shown in FIG. 31, at the long focal length extremitywhen focused on an object at infinity;

FIGS. 38A, 38B and 38C show lateral aberrations that occurred in thelens arrangement shown in FIG. 31 when the image-stabilizing lens groupis decentered, at the short focal length extremity when focused on anobject at infinity;

FIGS. 39A, 39B and 39C show lateral aberrations that occurred in thelens arrangement shown in FIG. 31 when the image-stabilizing lens groupis decentered, at an intermediate focal length when focused on an objectat infinity;

FIGS. 40A, 40B and 40C show lateral aberrations that occurred in thelens arrangement shown in FIG. 31 when the image-stabilizing lens groupis decentered, at the long focal length extremity when focused on anobject at infinity;

FIG. 41 shows a lens arrangement of a fifth numerical embodiment of azoom lens system, according to the present invention, at the short focallength extremity when focused on an object at infinity;

FIGS. 42A, 42B, 42C and 42D show various aberrations that occurred inthe lens arrangement shown in FIG. 41, at the short focal lengthextremity when focused on an object at infinity;

FIGS. 43A, 43B and 43C show lateral aberrations that occurred in thelens arrangement shown in FIG. 41, at the short focal length extremitywhen focused on an object at infinity;

FIGS. 44A, 44B, 44C and 44D show various aberrations that occurred inthe lens arrangement shown in FIG. 41, at an intermediate focal lengthwhen focused on an object at infinity;

FIGS. 45A, 45B and 45C show lateral aberrations that occurred in thelens arrangement shown in FIG. 41, at an intermediate focal length whenfocused on an object at infinity;

FIGS. 46A, 46B, 46C and 46D show various aberrations that occurred inthe lens arrangement shown in FIG. 41, at the long focal lengthextremity when focused on an object at infinity;

FIGS. 47A, 47B and 47C show lateral aberrations that occurred in thelens arrangement shown in FIG. 41, at the long focal length extremitywhen focused on an object at infinity;

FIGS. 48A, 48B and 48C show lateral aberrations that occurred in thelens arrangement shown in FIG. 41 when the image-stabilizing lens groupis decentered, at the short focal length extremity when focused on anobject at infinity;

FIGS. 49A, 49B and 49C show lateral aberrations that occurred in thelens arrangement shown in FIG. 41 when the image-stabilizing lens groupis decentered, at an intermediate focal length when focused on an objectat infinity;

FIGS. 50A, 50B and 50C show lateral aberrations that occurred in thelens arrangement shown in FIG. 41 when the image-stabilizing lens groupis decentered, at the long focal length extremity when focused on anobject at infinity;

FIG. 51 shows a lens arrangement of a sixth numerical embodiment of azoom lens system, according to the present invention, at the short focallength extremity when focused on an object at infinity;

FIGS. 52A, 52B, 52C and 52D show various aberrations that occurred inthe lens arrangement shown in FIG. 51, at the short focal lengthextremity when focused on an object at infinity;

FIGS. 53A, 53B and 53C show lateral aberrations that occurred in thelens arrangement shown in FIG. 51, at the short focal length extremitywhen focused on an object at infinity;

FIGS. 54A, 54B, 54C and 54D show various aberrations that occurred inthe lens arrangement shown in FIG. 51, at an intermediate focal lengthwhen focused on an object at infinity;

FIGS. 55A, 55B and 55C show lateral aberrations that occurred in thelens arrangement shown in FIG. 51, at an intermediate focal length whenfocused on an object at infinity;

FIGS. 56A, 56B, 56C and 56D show various aberrations that occurred inthe lens arrangement shown in FIG. 51, at the long focal lengthextremity when focused on an object at infinity;

FIGS. 57A, 57B and 57C show lateral aberrations that occurred in thelens arrangement shown in FIG. 51, at the long focal length extremitywhen focused on an object at infinity;

FIGS. 58A, 58B and 58C show lateral aberrations that occurred in thelens arrangement shown in FIG. 51 when the image-stabilizing lens groupis decentered, at the short focal length extremity when focused on anobject at infinity;

FIGS. 59A, 59B and 59C show lateral aberrations that occurred in thelens arrangement shown in FIG. 51 when the image-stabilizing lens groupis decentered, at an intermediate focal length when focused on an objectat infinity;

FIGS. 60A, 60B and 60C show lateral aberrations that occurred in thelens arrangement shown in FIG. 51 when the image-stabilizing lens groupis decentered, at the long focal length extremity when focused on anobject at infinity;

FIG. 61 shows a lens arrangement of a seventh numerical embodiment of azoom lens system, according to the present invention, at the short focallength extremity when focused on an object at infinity;

FIGS. 62A, 62B, 62C and 62D show various aberrations that occurred inthe lens arrangement shown in FIG. 61, at the short focal lengthextremity when focused on an object at infinity;

FIGS. 63A, 63B and 63C show lateral aberrations that occurred in thelens arrangement shown in FIG. 61, at the short focal length extremitywhen focused on an object at infinity;

FIGS. 64A, 64B, 64C and 64D show various aberrations that occurred inthe lens arrangement shown in FIG. 61, at an intermediate focal lengthwhen focused on an object at infinity;

FIGS. 65A, 65B and 65C show lateral aberrations that occurred in thelens arrangement shown in FIG. 61, at an intermediate focal length whenfocused on an object at infinity;

FIGS. 66A, 66B, 66C and 66D show various aberrations that occurred inthe lens arrangement shown in FIG. 61, at the long focal lengthextremity when focused on an object at infinity;

FIGS. 67A, 67B and 67C show lateral aberrations that occurred in thelens arrangement shown in FIG. 61, at the long focal length extremitywhen focused on an object at infinity;

FIG. 68 shows a lens arrangement of an eighth numerical embodiment of azoom lens system, according to the present invention, at the short focallength extremity when focused on an object at infinity;

FIGS. 69A, 69B, 69C and 69D show various aberrations that occurred inthe lens arrangement shown in FIG. 68, at the short focal lengthextremity when focused on an object at infinity;

FIGS. 70A, 70B and 70C show lateral aberrations that occurred in thelens arrangement shown in FIG. 68, at the short focal length extremitywhen focused on an object at infinity;

FIGS. 71A, 71B, 71C and 71D show various aberrations that occurred inthe lens arrangement shown in FIG. 68, at an intermediate focal lengthwhen focused on an object at infinity;

FIGS. 72A, 72B and 72C show lateral aberrations that occurred in thelens arrangement shown in FIG. 68, at an intermediate focal length whenfocused on an object at infinity;

FIGS. 73A, 73B, 73C and 73D show various aberrations that occurred inthe lens arrangement shown in FIG. 68, at the long focal lengthextremity when focused on an object at infinity;

FIGS. 74A, 74B and 74C show lateral aberrations that occurred in thelens arrangement shown in FIG. 68, at the long focal length extremitywhen focused on an object at infinity;

FIG. 75 shows a lens arrangement of a ninth numerical embodiment of azoom lens system, according to the present invention, at the short focallength extremity when focused on an object at infinity;

FIGS. 76A, 76B, 76C and 76D show various aberrations that occurred inthe lens arrangement shown in FIG. 75, at the short focal lengthextremity when focused on an object at infinity;

FIGS. 77A, 77B and 77C show lateral aberrations that occurred in thelens arrangement shown in FIG. 75, at the short focal length extremitywhen focused on an object at infinity;

FIGS. 78A, 78B, 78C and 78D show various aberrations that occurred inthe lens arrangement shown in FIG. 75, at an intermediate focal lengthwhen focused on an object at infinity;

FIGS. 79A, 79B and 79C show lateral aberrations that occurred in thelens arrangement shown in FIG. 75, at an intermediate focal length whenfocused on an object at infinity;

FIGS. 80A, 80B, 80C and 80D show various aberrations that occurred inthe lens arrangement shown in FIG. 75, at the long focal lengthextremity when focused on an object at infinity;

FIGS. 81A, 81B and 81C show lateral aberrations that occurred in thelens arrangement shown in FIG. 75, at the long focal length extremitywhen focused on an object at infinity;

FIG. 82 shows a lens arrangement of a tenth numerical embodiment of azoom lens system, according to the present invention, at the short focallength extremity when focused on an object at infinity;

FIGS. 83A, 83B, 83C and 83D show various aberrations that occurred inthe lens arrangement shown in FIG. 82, at the short focal lengthextremity when focused on an object at infinity;

FIGS. 84A, 84B and 84C show lateral aberrations that occurred in thelens arrangement shown in FIG. 82, at the short focal length extremitywhen focused on an object at infinity;

FIGS. 85A, 85B, 85C and 85D show various aberrations that occurred inthe lens arrangement shown in FIG. 82, at an intermediate focal lengthwhen focused on an object at infinity;

FIGS. 86A, 86B and 86C show lateral aberrations that occurred in thelens arrangement shown in FIG. 82, at an intermediate focal length whenfocused on an object at infinity;

FIGS. 87A, 87B, 87C and 87D show various aberrations that occurred inthe lens arrangement shown in FIG. 82, at the long focal lengthextremity when focused on an object at infinity;

FIGS. 88A, 88B and 88C show lateral aberrations that occurred in thelens arrangement shown in FIG. 82, at the long focal length extremitywhen focused on an object at infinity;

FIG. 89 shows a lens arrangement of an eleventh numerical embodiment ofa zoom lens system, according to the present invention, at the shortfocal length extremity when focused on an object at infinity;

FIGS. 90A, 90B, 90C and 90D show various aberrations that occurred inthe lens arrangement shown in FIG. 89, at the short focal lengthextremity when focused on an object at infinity;

FIGS. 91A, 91B and 91C show lateral aberrations that occurred in thelens arrangement shown in FIG. 89, at the short focal length extremitywhen focused on an object at infinity;

FIGS. 92A, 92B, 92C and 92D show various aberrations that occurred inthe lens arrangement shown in FIG. 89, at an intermediate focal lengthwhen focused on an object at infinity;

FIGS. 93A, 93B and 93C show lateral aberrations that occurred in thelens arrangement shown in FIG. 89, at an intermediate focal length whenfocused on an object at infinity;

FIGS. 94A, 94B, 94C and 94D show various aberrations that occurred inthe lens arrangement shown in FIG. 89, at the long focal lengthextremity when focused on an object at infinity;

FIGS. 95A, 95B and 95C show lateral aberrations that occurred in thelens arrangement shown in FIG. 89, at the long focal length extremitywhen focused on an object at infinity;

FIG. 96 shows a lens arrangement of a twelfth numerical embodiment of azoom lens system, according to the present invention, at the short focallength extremity when focused on an object at infinity;

FIGS. 97A, 97B, 97C and 97D show various aberrations that occurred inthe lens arrangement shown in FIG. 96, at the short focal lengthextremity when focused on an object at infinity;

FIGS. 98A, 98B and 98C show lateral aberrations that occurred in thelens arrangement shown in FIG. 96, at the short focal length extremitywhen focused on an object at infinity;

FIGS. 99A, 99B, 99C and 99D show various aberrations that occurred inthe lens arrangement shown in FIG. 96, at an intermediate focal lengthwhen focused on an object at infinity;

FIGS. 100A, 100B and 100C show lateral aberrations that occurred in thelens arrangement shown in FIG. 96, at an intermediate focal length whenfocused on an object at infinity;

FIGS. 101A, 101B, 101C and 101D show various aberrations that occurredin the lens arrangement shown in FIG. 96, at the long focal lengthextremity when focused on an object at infinity;

FIGS. 102A, 102B and 102C show lateral aberrations that occurred in thelens arrangement shown in FIG. 96, at the long focal length extremitywhen focused on an object at infinity;

FIG. 103 shows a lens arrangement of a thirteenth numerical embodimentof a zoom lens system, according to the present invention, at the shortfocal length extremity when focused on an object at infinity;

FIGS. 104A, 104B, 104C and 104D show various aberrations that occurredin the lens arrangement shown in FIG. 103, at the short focal lengthextremity when focused on an object at infinity;

FIGS. 105A, 105B and 105C show lateral aberrations that occurred in thelens arrangement shown in FIG. 103, at the short focal length extremitywhen focused on an object at infinity;

FIGS. 106A, 106B, 106C and 106D show various aberrations that occurredin the lens arrangement shown in FIG. 103, at an intermediate focallength when focused on an object at infinity;

FIGS. 107A, 107B and 107C show lateral aberrations that occurred in thelens arrangement shown in FIG. 103, at an intermediate focal length whenfocused on an object at infinity;

FIGS. 108A, 108B, 108C and 108D show various aberrations that occurredin the lens arrangement shown in FIG. 103, at the long focal lengthextremity when focused on an object at infinity;

FIGS. 109A, 109B and 109C show lateral aberrations that occurred in thelens arrangement shown in FIG. 103, at the long focal length extremitywhen focused on an object at infinity;

FIG. 110 shows a lens arrangement of a fourteenth numerical embodimentof a zoom lens system, according to the present invention, at the shortfocal length extremity when focused on an object at infinity;

FIGS. 111A, 111B, 111C and 111D show various aberrations that occurredin the lens arrangement shown in FIG. 110, at the short focal lengthextremity when focused on an object at infinity;

FIGS. 112A, 112B and 112C show lateral aberrations that occurred in thelens arrangement shown in FIG. 110, at the short focal length extremitywhen focused on an object at infinity;

FIGS. 113A, 113B, 113C and 113D show various aberrations that occurredin the lens arrangement shown in FIG. 110, at an intermediate focallength when focused on an object at infinity;

FIGS. 114A, 114B and 114C show lateral aberrations that occurred in thelens arrangement shown in FIG. 110, at an intermediate focal length whenfocused on an object at infinity;

FIGS. 115A, 115B, 115C and 115D show various aberrations that occurredin the lens arrangement shown in FIG. 110, at the long focal lengthextremity when focused on an object at infinity;

FIGS. 116A, 116B and 116C show lateral aberrations that occurred in thelens arrangement shown in FIG. 110, at the long focal length extremitywhen focused on an object at infinity;

FIG. 117 shows a lens arrangement of a fifteenth numerical embodiment ofa zoom lens system, according to the present invention, at the shortfocal length extremity when focused on an object at infinity;

FIGS. 118A, 118B, 118C and 118D show various aberrations that occurredin the lens arrangement shown in FIG. 117, at the short focal lengthextremity when focused on an object at infinity;

FIGS. 119A, 119B and 119C show lateral aberrations that occurred in thelens arrangement shown in FIG. 117, at the short focal length extremitywhen focused on an object at infinity;

FIGS. 120A, 120B, 120C and 120D show various aberrations that occurredin the lens arrangement shown in FIG. 117, at an intermediate focallength when focused on an object at infinity;

FIGS. 121A, 121B and 121C show lateral aberrations that occurred in thelens arrangement shown in FIG. 117, at an intermediate focal length whenfocused on an object at infinity;

FIGS. 122A, 122B, 122C and 122D show various aberrations that occurredin the lens arrangement shown in FIG. 117, at the long focal lengthextremity when focused on an object at infinity;

FIGS. 123A, 123B and 123C show lateral aberrations that occurred in thelens arrangement shown in FIG. 117, at the long focal length extremitywhen focused on an object at infinity;

FIG. 124 shows a first zoom path of the zoom lens system according tothe present invention;

FIG. 125 shows a second zoom path of the zoom lens system according tothe present invention; and

FIG. 126 shows a third zoom path of the zoom lens system according tothe present invention.

DESCRIPTION OF THE EMBODIMENTS

The illustrated embodiments of the zoom lens system include a “firstaspect of the present invention”, to which the first through sixthnumerical embodiments belong, and a “second aspect of the presentinvention”, to which the seventh through fifteenth numerical embodimentsbelong.

First Aspect of Present Invention

As shown in the zoom path diagrams in FIGS. 124 and 125, the zoom lenssystem of the first through sixth numerical embodiments is configured ofa negative first lens group G1, a positive second lens group G2, anegative third lens group G3 and a positive fourth lens group G4, inthat order from the object side. The third lens group G3 is configuredof a negative first sub-lens group G3 a and a negative second sub-lensgroup G3 b, in that order from the object side. A diaphragm S ispositioned between the second lens group G2 and the third lens group G3,and the diaphragm S integrally moves with the second lens group G2during a zooming operation. “I” designates the image plane.

As shown in the zoom path diagrams in FIGS. 124 and 125, in the zoomlens system of the first through sixth numerical embodiments, uponzooming from the short focal length extremity (Wide) to the long focallength extremity (Tele), the distance between the first lens group G1and the second lens group G2 decreases, the distance between the secondlens group G2 and the third lens group G3 increases, and the distancebetween the third lens group G3 and the fourth lens group G4 decreases.

In each of the first through sixth embodiments, upon zooming from theshort focal length extremity to the long focal length extremity, thefirst lens group G1 either monotonically moves toward the image side orfirst moves toward the image side and thereafter moves (returns)slightly toward the object side. It is possible, in an alternativeembodiment, for the first lens group G1, upon zooming from the shortfocal length extremity to the long focal length extremity, to movetoward the object side or first move toward the object (image) side andthereafter move toward the image (object) side to return to (U-turn) theshort focal length extremity.

In each of the first through sixth embodiments, upon zooming from theshort focal length extremity to the long focal length extremity, thesecond lens group G2 and the fourth lens group G4 monotonically movetoward the object side.

In each of the first, second and fourth through sixth numericalembodiments, as shown in the zoom path diagram of FIG. 124, upon zoomingfrom the short focal length extremity to the long focal lengthextremity, the third lens group G3 does not move in the optical axisdirection (the third lens group G3 remains stationary relative to theimage plane I). In the third numerical embodiment, as shown in the zoompath diagram of FIG. 125, upon zooming from the short focal lengthextremity to the long focal length extremity, the third lens group G3moves toward the object side.

In each of the first through sixth numerical embodiments, the first lensgroup G1 is configured of a negative meniscus lens element 11 having aconvex surface on the object side, a negative meniscus lens element 12having a convex surface on the object side, a biconcave negative lenselement 13 and a biconvex positive lens element 14, in that order fromthe object side. The negative meniscus lens element 11 is a hybrid lensformed by a glass lens element with an aspherical surface layer, formedfrom a synthetic resin material, adhered onto the image side thereof.

In each of the first through sixth numerical embodiments, the secondlens group G2 is configured of a positive meniscus lens element 21having a convex surface on the object side, a cemented lens formed by anegative meniscus lens element 22 having a convex surface on the objectside, and a biconvex positive lens element 23; and a biconvex positivelens element 24, in that order from the object side.

In each of the first through sixth numerical embodiments, the firstsub-lens group G3 a is configured of a cemented lens formed by abiconcave negative lens element 31 and a biconvex positive lens element32, in that order from the object side.

In each of the first through sixth numerical embodiments, the secondsub-lens group G3 b serves as an image-shake correction lens group(image-stabilizing lens group) which corrects image shake that is causedby hand shake/vibrations, etc., by moving (decentering) the image-shakecorrection lens group in a direction orthogonal to the optical axis tothereby change the imaging position.

In each of the first, second, fourth and fifth numerical embodiments,the second sub-lens group G3 b is configured of a biconcave negativelens element (a negative single lens element having a concave surface onthe image side) 33 and a positive meniscus lens element (a positivesingle lens element having a convex surface on the object side) 34having convex surface on the object side, in that order from the objectside, and an air lens having a meniscus shape with a convex surface onthe object side is formed between the biconcave negative lens element 33and the positive meniscus lens element 34.

In the third numerical embodiment, the second sub-lens group G3 b isconfigured of a negative meniscus lens element (a negative single lenselement having a concave surface on the image side) 33 having a convexsurface on the object side and a positive meniscus lens element 34having convex surface on the object side (a positive single lens elementhaving a convex surface on the object side), in that order from theobject side, and an air lens having a meniscus shape having a convexsurface on the object side is formed between the negative meniscus lenselement 33 and the positive meniscus lens element 34.

In the sixth numerical embodiment, the second sub-lens group G3 b isconfigured of a biconcave negative lens element (a negative single lenselement having a concave surface on the image side) 33 and a biconvexpositive lens element (a positive single lens element having a convexsurface on the object side) 34, in that order from the object side, andan air lens having a meniscus shape with a convex surface on the objectside is formed between the biconcave negative lens element 33 and thebiconvex positive lens element 34.

In each of the first through third numerical embodiments, the fourthlens group G4 is configured of a cemented lens provided with a biconvexpositive lens element 41, a biconcave negative lens element 42 and abiconvex positive lens element 43; and a cemented lens provided with abiconcave negative lens element 44 and a biconvex positive lens element45, in that order from the object side. The biconcave negative lenselement 44 is a hybrid lens formed by a glass lens element with anaspherical surface layer, formed from a synthetic resin material,adhered onto the object side thereof.

In each of the fourth through sixth numerical embodiments, the fourthlens group G4 is configured of a cemented lens provided with aplanoconvex positive lens element 41 having a convex surface on theobject side, a planoconcave negative lens element 42 having a concavesurface on the image side, and a biconvex positive lens element 43; anda cemented lens provided with a biconcave negative lens element 44 and abiconvex positive lens element 45, in that order from the object side.The biconcave negative lens element 44 is a hybrid lens formed by aglass lens element with an aspherical surface layer, formed from asynthetic resin material, adhered onto the object side thereof.

The zoom lens system of the first aspect of the present inventionassumes a negative-lead configuration having four lens groups, namely, anegative lens group, a positive lens group, a negative lens group and apositive lens group, in that order from the object side. In this assumedconfiguration, the negative third lens group G3 is divided into thenegative first sub-lens group G3 a and the negative second sub-lensgroup G3 b. Furthermore, the second sub-lens group G3 b is configured ofthe negative single lens element 33 and the positive single lens element34, and an air lens is formed between the negative single lens element33 and the positive single lens element 34. In other words, the negativesingle lens element 33 and the positive single lens element 34 are notcemented to each other and are provided spaced apart with air existingtherebetween.

As described above, the second sub-lens group G3 b serves as animage-shake correction lens group (image-stabilizing lens group) whichcorrects image shake that is caused by hand shake/vibrations, etc., bymoving (decentering) the image-shake correction lens group in adirection orthogonal to the optical axis to thereby change the imagingposition.

In the zoom lens system according to the first aspect of the presentinvention, by appropriately determining the arrangement and refractivepower of the second sub-lens group G3 b, which serves as animage-stabilizing lens group, aberration fluctuations in a normal state(a state in which decentering of the image-stabilizing lens group is notbeing carried out) and in an image-stabilizing driving state (a state inwhich decentering of the image-stabilizing lens group is being carriedout) are suppressed, and aberrations occurring during animage-stabilizing drive operation in particular are favorably corrected,thereby successfully achieving a superior optical quality.

By configuring the second sub-lens group G3 b, which serves as theimage-stabilizing lens group, with the negative single lens element 33and the positive single lens element 34, decentration chromaticaberration can be favorably corrected. Furthermore, by forming the airlens between the negative single lens element 33 and the positive singlelens element 34, the freedom in aberration correction is increased, anddecentration coma that occurs during the decentering of the secondsub-lens group G3 b, serving as the image-stabilizing lens group, can befavorably corrected.

Furthermore, by forming the negative single lens element 33 to have aconcave surface on the image side (either a biconcave shape or ameniscus shape with a convex surface on the object side) and by formingthe positive single lens element 34 to have a convex surface on theobject side (either a biconvex shape or a meniscus shape with a convexsurface on the object side), and by forming both sides of the air lens,which is formed (defined) between the negative single lens element 33and the positive single lens element 34, as convex surfaces facing theobject side (a meniscus shape having a convex surface on the objectside), spherical aberration can be favorably corrected, and decentrationcoma that occurs during the decentering of the second sub-lens group G3b, serving as the image-stabilizing lens group, can be favorablycorrected.

It is desirable for the focal length of the air lens formed between thenegative single lens element 33 and the positive single lens element 34within the second sub-lens group G3 b to be a positive value. If thefocal length of the air lens within the second sub-lens group G3 b wereto have a negative value, an excessive cancelling out of sphericalaberration would occur at each side of the air lens so that aberrationfluctuations, due to decentration between the surfaces of the air lens,increase, so that it would be difficult to maintain a practical opticalquality.

In the zoom lens system according to the first aspect of the presentinvention, the optical quality during the image-stabilizing driveoperation is increased without relying on using methods such asincreasing the number of lens elements in the image-stabilizing lensgroup or using aspherical surfaces within the image-stabilizing lensgroup. In other words, the second sub-lens group G3 b, serving as animage-stabilizing lens group, is configured of two lens elements, i.e.,the negative single lens element 33 and the positive single lens element34, and no aspherical lens elements are used within the second sub-lensgroup G3 b. Accordingly, the burden on the drive mechanism for theimage-stabilizing lens group is reduced, the entire zoom lens system(and also the entire apparatus including the drive mechanism for theimage-stabilizing lens group) can be miniaturized, and the manufacturingcost can be reduced.

In the zoom lens system according to the first aspect of the presentinvention, in the first, second and fourth through sixth numericalembodiments, the third lens group G3 does not move in the optical axisdirection during zooming from the short focal length extremity to thelong focal length extremity (the third lens group G3 remains stationaryrelative to the image plane I). Accordingly, by reducing the number ofmovable parts that move during a zooming operation, the mechanicalstructure of the lens frames can be simplified, thereby suppressingmanufacturing costs. Furthermore, since causes for manufacturing errorare reduced, the configuration according to the first aspect of thepresent invention is advantageous for maintaining a practical opticalquality. Furthermore, if the second sub-lens group G3 b serves as animage-stabilizing lens group, as with the case of the first aspect ofthe present invention, since the image-stabilizing drive mechanism canbe configured separately from the zooming mechanism, this enables theouter diameter of the zoom lens system to be reduced.

On the other hand, in the third numerical embodiment, the third lensgroup G3 moves in the optical axis direction during zooming from theshort focal length extremity to the long focal length extremity.Accordingly, since the freedom in correcting aberration fluctuationswhich accompany a zooming operation is increased, this is advantageousfor aberration correction.

Hence, the zoom lens system according to the first aspect of the presentinvention can be implemented regardless of whether or not the third lensgroup G3 moves in the optical axis direction during a zooming operation.

The zoom lens system of the first aspect of the present invention is anoptical system which is especially suitable for use in a single-lensreflex camera, however, the photographing apparatus to which the zoomlens system of the first aspect of the present invention can be appliedcan be a single-lens reflex camera or a so-called non-reflex(mirrorless) camera that does not have a quick-return mirror.

In the zoom lens system of the first aspect of the present invention,although the second sub-lens group G3 b serves as the image-stabilizinglens group, even if the zoom lens system uses a lens group other thanthe second sub-lens group G3 b as the image-stabilizing lens group oreven if the zoom lens system is not provided with an image-stabilizingfunction, a high optical quality can be achieved since the designfreedom can be increased due to the air lens that is formed within thesecond sub-lens group G3 b. In other words, it is not essential to thepresent invention for the second sub-lens group G3 b to serve as animage-stabilizing lens group.

Condition (1) specifies the shape of the air lens within the secondsub-lens group G3 b. By satisfying condition (1), aberrationfluctuations due to decentration between the surfaces of the air lenscan be reduced so that a practical optical quality is maintained, anddecentration coma that occurs during the decentering of the secondsub-lens group G3 b, serving as the image-stabilizing lens group, can befavorably corrected.

If the upper limit of condition (1) is exceeded, an excessive cancellingout of spherical aberration would occur at each side of the air lens sothat aberration fluctuations, due to decentration between the surfacesof the air lens, increase, thereby causing difficulties in maintaining apractical optical quality.

If the lower limit of condition (1) is exceeded, correction ofdecentration coma that occurs during the decentering of the secondsub-lens group G3 b, serving as the image-stabilizing lens group,becomes insufficient.

Condition (2) specifies the shape of the first sub-lens group G3 a. Bysatisfying condition (2), axial chromatic aberration that occurs duringzooming and fluctuations in lateral chromatic aberration that occurduring zooming can be suppressed while coma can be favorably corrected.

If the upper limit of condition (2) is exceeded, axial chromaticaberration that occurs during zooming and fluctuations in lateralchromatic aberration that occur during zooming increase.

If the lower limit of condition (2) is exceeded, correction of comabecomes insufficient.

Condition (3) specifies the shape of the air lens between the firstsub-lens group G3 a and the second sub-lens group G3 b. By satisfyingcondition (3), axial chromatic aberration that occurs during zooming andfluctuations in lateral chromatic aberration that occur during zoomingcan be suppressed while coma, especially decentration coma that occursduring the decentering of the second sub-lens group G3 b (serving as theimage-stabilizing lens group), can be favorably corrected.

If the upper limit of condition (3) is exceeded, correction of comabecomes insufficient.

If the lower limit of condition (3) is exceeded, axial chromaticaberration that occurs during zooming and fluctuations in lateralchromatic aberration that occur during zooming increase.

Conditions (4) and (5) specify the image-stabilizing sensitivityindicated by image-shake amount per unit amount of decentering carriedout by the second sub-lens group G3 b, serving as the image-stabilizinglens group. By satisfying conditions (4) and (5), the movement amount(orthogonal to the optical axis) of the second sub-lens group G3 b(serving as the image-stabilizing lens group) can appropriatelydetermined and aberration fluctuations that occur during a decenteringoperation by the second sub-lens group G3 b can be favorably corrected.

If the upper limits of conditions (4) and (5) are exceeded, theimage-stabilizing sensitivity becomes excessively small so that themovement amount of the image-stabilizing lens group increases greatlywith respect to the same amount of image shake, and the burden on thedrive mechanism for the image-stabilizing lens group increases, which isundesirable.

If the lower limits of conditions (4) and (5) are exceeded, therefractive power of the image-stabilizing lens group becomes excessivelylarge, requiring a highly precise positional control of theimage-stabilizing lens group when correctly image shake. Furthermore, itbecomes difficult to correct decentration coma that occurs during thedecentering of the second sub-lens group G3 b.

Second Aspect of Present Invention

As shown in the zoom path diagram in FIG. 126, the zoom lens system ofthe seventh through fifteenth numerical embodiments is configured of anegative first lens group G1, a positive second lens group G2, anegative third lens group G3 and a positive fourth lens group G4, inthat order from the object side. The second lens group G2 is configuredof a positive first sub-lens group G2 a and a positive second sub-lensgroup G2 b, in that order from the object side. The first sub-lens groupG2 a serves as a focusing lens group which moves in the optical axisdirection (toward the image side) during a focusing operation. Thefourth lens group G4 is configured of a positive third sub-lens group G4a and a negative fourth sub-lens group G4 b, in that order from theobject side. A diaphragm S is positioned between the second lens groupG2 and the third lens group G3, and the diaphragm S integrally moveswith the second lens group G2 during a zooming operation. “I” designatesthe image plane.

As shown in the zoom path diagram in FIG. 126, in the zoom lens systemof the seventh through fifteenth numerical embodiments, upon zoomingfrom the short focal length extremity (Wide) to the long focal lengthextremity (Tele), the distance between the first lens group G1 and thesecond lens group G2 decreases, the distance between the second lensgroup G2 and the third lens group G3 increases, and the distance betweenthe third lens group G3 and the fourth lens group G4 decreases.

In each of the seventh through fifteenth embodiments, upon zooming fromthe short focal length extremity to the long focal length extremity, thefirst lens group G1 moves toward the image side by a slight amount. Itis possible, in an alternative embodiment, for the first lens group G1,upon zooming from the short focal length extremity to the long focallength extremity, to move toward the object side or to move in a U-turnat an intermediate focal length position.

In each of the seventh through fifteenth embodiments, upon zooming fromthe short focal length extremity to the long focal length extremity, thesecond lens group G2 and the fourth lens group G4 monotonically move(advance) toward the object side. The movement amount (advancing amount)of the fourth lens group G4 is greater than the movement amount(advancing amount) of the second lens group G2.

In each of the seventh through ninth and eleventh through thirteenthnumerical embodiments, as shown by the broken line in the zoom pathdiagram of FIG. 126, upon zooming from the short focal length extremityto the long focal length extremity, the third lens group G3 does notmove in the optical axis direction (the third lens group G3 remainsstationary relative to the image plane I). Accordingly, by reducing thenumber of movable parts that move during a zooming operation, themechanical structure of the lens frames can be simplified, therebysuppressing manufacturing costs. Furthermore, since causes formanufacturing error are reduced, the configuration according to thesecond aspect of the present invention is advantageous for maintaining apractical optical quality.

In the tenth, fourteenth and fifteenth numerical embodiments, as shownby the solid line in the zoom path of FIG. 126, upon zooming from theshort focal length extremity to the long focal length extremity, thethird lens group G3 first moves toward the image side and thereaftermoves toward the object side by a slight amount past the short focallength extremity position. Accordingly, since the freedom in the zoomlens system increases, this is advantageous for correcting aberrationfluctuations which occur during a zooming operation. Furthermore, anappropriate zoom path other than the those illustrated can be selectedfor the zoom path of the third lens group G3 for the purpose ofcorrecting field curvature.

Hence, the zoom lens system according to the second aspect of thepresent invention can be implemented regardless of whether or not thethird lens group G3 moves in the optical axis direction during a zoomingoperation.

In each of the seventh through fifteenth numerical embodiments, thefirst lens group G1 is configured of a negative meniscus lens element 11having a convex surface on the object side (a negative lens elementhaving a convex surface on the object side), a negative meniscus lenselement 12 having a convex surface on the object side (a negative lenselement having a convex surface on the object side), a biconcavenegative lens element 13 and a biconvex positive lens element (apositive lens element having a convex surface on the object side) 14, inthat order from the object side. The negative meniscus lens element 11is a hybrid lens formed by a glass lens element with an asphericalsurface layer, formed from a synthetic resin material, adhered onto theimage side thereof.

In each of the seventh through fifteenth numerical embodiments, thefirst sub-lens group G2 a is configured of a positive meniscus lenselement 21 having a convex surface on the object side (positive lenselement having a convex surface on the object side), and a cemented lensprovided with a negative meniscus lens element 22 having a convexsurface on the object side (a negative lens element having a convexsurface on the object side), and a biconvex positive lens element 23, inthat order from the object side.

In each of the seventh through fifteenth numerical embodiments, thesecond sub-lens group G2 b is configured of a biconvex positive lenselement 24.

In each of the seventh through fifteenth numerical embodiments, thethird lens group G3 is configured of a cemented lens provided with abiconcave negative lens element 31 and a biconvex positive lens element32; a biconcave negative lens element 33 and a positive meniscus lenselement 34 having a convex surface on the object side, in that orderfrom the object side.

In each of the seventh, eighth and eleventh numerical embodiments, thethird sub-lens group G4 a is configured of a cemented lens provided witha biconvex positive lens element (a positive lens element having aconvex surface on the object side) 41, a biconcave negative lens element42 and a biconvex positive lens element 43, in that order from theobject side.

In each of the ninth, tenth and twelfth through fifteenth numericalembodiments, the third sub-lens group G4 a is configured of a cementedlens provided with a planoconvex positive lens element 41 having aconvex surface on the object side (a positive lens element having aconvex surface on the object side), a planoconcave negative lens element42 having a concave surface on the image side, and a biconvex positivelens element 43, in that order from the object side.

In each of the seventh through eleventh and thirteenth through fifteenthnumerical embodiments, the fourth sub-lens group G4 b is configured of acemented lens having a biconcave negative lens element 44 and a biconvexpositive lens element 45, in that order from the object side. Thebiconcave negative lens element 44 is a hybrid lens formed by a glasslens element with an aspherical surface layer, formed from a syntheticresin material, adhered onto the object side thereof.

In the twelfth numerical embodiment, the fourth sub-lens group G4 b isconfigured of a cemented lens provided with negative meniscus lenselement 44 having a convex surface on the object side, and a biconvexpositive lens element 45, in that order from the object side. Thenegative meniscus lens element 44 is a hybrid lens formed by a glasslens element with an aspherical surface layer, formed from a syntheticresin material, adhered onto the object side thereof.

In the zoom lens system according to the second aspect of the presentinvention, the second lens group G2 possesses the main zooming function,the first lens group G1 corrects the fluctuation in the focal positionthat occurs during zooming, and the third and fourth lens groups G3 andG4 correct fluctuations in aberrations, such as spherical aberration andfield curvature, which occur during zooming; furthermore, byappropriately determining the refractive power distribution and thezooming movement amount of the first through fourth lens groups G1through G4, which have the above-mentioned roles, a favorable opticalquality can be successfully achieved in which fluctuations inaberrations are suppressed over the entire focal length range and overthe entire photographing distance range.

Condition (6) specifies the ratio of the movement amount in the opticalaxis direction of the second lens group G2 (movement amount relative tothe image plane I) to the movement amount in the optical axis directionof the fourth lens group G4 (movement amount relative to the image planeI) when zooming from the short focal length extremity to the long focallength extremity. In the zoom lens system according to the second aspectof the present invention, not only is the movement amount of the secondlens group G2 which possesses the main zooming function important, sincethe zooming movement amount of the third lens group G3 is either zero orvery small, the appropriate determining of the change in air distancebetween the third lens group G3 and the fourth lens group G4 (whichcorrect aberration fluctuations that occur during zooming), i.e., themovement amount of the fourth lens group G4, also becomes important. Bydetermining the ratio of the zooming movement amounts of the second lensgroup G2 and the fourth lens group G4 in order to satisfy condition (6),fluctuation in field curvature that occurs during zooming can besuppressed, and a favorable optical quality can be achieved.

If the upper limit of condition (6) is exceeded, it becomes difficult tocorrect fluctuations in field curvature that occur during zooming.Furthermore, the overall length of the zoom lens system increases, sothat in order to collect a sufficient quantity of peripheral light, theeffective diameter and weight of the first lens group G1 is increased,which undesirably causes an increase in manufacturing costs.

If the lower limit of condition (6) is exceeded, although advantageousfor reducing the overall length of the zoom lens system, it becomesdifficult to correct fluctuations in field curvature that occur duringzooming.

Condition (7) specifies the ratio of the focal length of the first lensgroup G1 to the focal length of the second lens group G2. By satisfyingcondition (7), the distribution of the refractive powers of the firstlens group G1 and the second lens group G2 can be appropriatelydetermined, so that fluctuation in field curvature that occurs duringzooming can be suppressed, and a favorable optical quality can beachieved.

If the upper limit of condition (7) is exceeded, although advantageousfor reducing the overall length of the zoom lens system, it becomesdifficult to correct fluctuations in field curvature that occur duringzooming.

If the lower limit of condition (7) is exceeded, it becomes difficult tocorrect fluctuations in field curvature that occur during zooming.Furthermore, the overall length of the zoom lens system increases, sothat in order to sufficient peripheral light, the effective diameter andweight of the first lens group G1 is increased, which undesirably causesan increase in manufacturing costs.

Condition (8) specifies the ratio of the focal length of the first lensgroup G1 to the focal length of the third lens group G3. By satisfyingcondition (8), the distribution of the refractive powers of the firstlens group G1 and the third lens group G3 can be appropriatelydetermined, so that fluctuation in field curvature that occurs duringzooming can be suppressed, and a favorable optical quality can beachieved.

If the upper limit of condition (8) is exceeded, it becomes difficult tocorrect fluctuations in field curvature that occur during zooming.Furthermore, the overall length of the zoom lens system increases, sothat in order to collect a sufficient quantity of light, the effectivediameter and weight of the first lens group G1 is increased, whichundesirably causes an increase in manufacturing costs.

If the lower limit of condition (8) is exceeded, although advantageousfor reducing the overall length of the zoom lens system, it becomesdifficult to correct fluctuations in field curvature that occur duringzooming.

Condition (9) specifies the ratio of the focal length of the first lensgroup G1 to the focal length of the fourth lens group G4. By satisfyingcondition (9), the distribution of the refractive powers of the firstlens group G1 and the fourth lens group G4 can be appropriatelydetermined, so that fluctuation in field curvature that occurs duringzooming can be suppressed, and a favorable optical quality can beachieved.

If the upper limit of condition (9) is exceeded, although advantageousfor reducing the overall length of the zoom lens system, it becomesdifficult to correct fluctuations in field curvature that occur duringzooming.

If the lower limit of condition (9) is exceeded, it becomes difficult tocorrect fluctuations in field curvature that occur during zooming.Furthermore, the overall length of the zoom lens system increases, sothat in order to collect sufficient peripheral light, the effectivediameter and weight of the first lens group G1 is increased, whichundesirably causes an increase in manufacturing costs.

By simultaneously satisfying conditions (7), (8) and (9), thedistribution of the refractive powers of the first through fourth lensgroups G1 through G4 can be appropriately determined so that fluctuationin field curvature that occurs during zooming can be further suppressedand an even more favorable optical quality can be achieved.

As described above, in the zoom lens system according to the secondaspect of the present invention, the second lens group G2 is configuredof a positive first sub-lens group G2 a and a positive second sub-lensgroup G2 b, in that order from the object side. The first sub-lens groupG2 a serves as a focusing lens group which moves in the optical axisdirection (toward the image side) during a focusing operation. Byappropriately determining the refractive power and lens arrangement ofthe first sub-lens group G2 a, serving as a focusing lens group,aberration fluctuations from infinity through to a close distance can besuppressed, and a favorable optical quality can be achieved.

The first sub-lens group G2 a is configured of a positive lens element21 having a convex surface on the object side, and a cemented lensprovided with a negative lens element 22 having a convex surface on theobject side and a positive lens element 23, in that order from theobject side. Due to a so-called “concentric” distribution of each sideof the positive lens element 21 and the object side of the positive lenselement 22 with respect to the diaphragm S, occurrence of abaxialaberrations such as coma and astigmatism can be suppressed. Furthermore,spherical aberration that occurs on the side closest to the object sideof the first sub-lens group G2 a can be corrected by the bondingsurface, having a convex surface on the object side, that is formed bythe negative lens element 22 and the positive lens element 23.

Conditions (10) and (11) specify the so-called “focusing sensitivity”which is determined by the lateral magnification of the first sub-lensgroup G2 a, serving as a focusing lens group, and the combined lateralmagnification of the lens groups behind of the first sub-lens group G2 a(i.e., the second sub-lens group G2 b, the third lens group G3 and thefourth lens group G4). By satisfying condition (10) or (11), anappropriate movement amount of the focusing lens group can bedetermined, and fluctuations in coma and chromatic aberration that occurduring a focusing operation can be suppressed.

If the upper limit of condition (10) or (11) is exceeded, since thefocusing sensitivity decreases, the movement amount of the focusing lensgroup during a focusing operation increases, which undesirably increasesthe burden on the autofocus mechanism thereof. Furthermore, since thedifference in the movement amount of the focusing lens group between theshort focal length extremity and the long focal length extremity whenfocusing on an object at a close distance is increased, fluctuation inthe focal position, which occurs during zooming in close-distancephotography, undesirably increases.

If the lower limit of condition (10) or (11) is exceeded, fluctuationsin coma, axial chromatic aberration and lateral chromatic aberration,which occur due to the movement of the focusing lens group in theoptical axis direction, increase, so that it becomes difficult toachieve a high optical quality.

By simultaneously satisfying conditions (10) and (11), the movementamount of the focusing lens group can be even more appropriatelydetermined, and fluctuations in coma and chromatic aberration that occurduring a focusing operation can be further suppressed. However,conditions (10) and (11) do not necessarily need to be simultaneouslysatisfied (conditions (10) and (11) are not integrally inseparable), azoom lens system satisfying one of conditions (10) and (11) can alsoexhibit the same effect to a certain degree, and can be included in thetechnical scope of the zoom lens system according to the presentinvention.

As described above, in the second aspect of the present invention, thefourth lens group G4 is configured of the positive third sub-lens groupG4 a and the negative fourth sub-lens group G4 b, in that order from theobject side; the third sub-lens group G4 a is formed as a cemented lensprovided with a positive lens element 41 having a convex surface on theobject side, a negative lens element 42, and a biconvex positive lenselement 43, in that order from the object side.

A high optical quality can be achieved by favorably correcting axialchromatic aberration and lateral chromatic aberration, occurring in thefirst through third lens groups G1 through G3, using the fourth lensgroup G4. If a lens material exhibiting a low refractive index and a lowdispersion is used for correcting chromatic aberration, although itbecomes more difficult to correct spherical aberration and coma, etc.,by forming the third sub-lens group G4 a as a cemented lens having threelens elements 41, 42 and 43 as in the second aspect of the presentinvention, the freedom in the correction of chromatic aberration and thecorrection of high-order spherical aberration and coma via the bondingsurfaces of the cemented lens can be increased.

Condition (12) specifies the difference between the average value of theAbbe numbers with respect to the d-line of the positive lens elements 41and 43 that are provided in the third sub-lens group G4 a, and the Abbenumber with respect to the d-line of the negative lens element 42 thatis provided in the third sub-lens group G4 a. By satisfying condition(12), axial chromatic aberration and lateral chromatic aberration can befavorably corrected.

If either of the upper or lower limits of condition (12) is exceeded, itbecomes difficult to suppress fluctuations in the chromatic aberrationthat occur during zooming.

Conditions (13) and (14) specify the ratio of the lateral magnificationof the second lens group G2 to the lateral magnification of the fourthlens group G4. By satisfying condition (13) or (14), fluctuations infield curvature that occur during zooming are suppressed so that afavorable optical quality can be achieved.

If the upper limit of condition (13) or (14) is exceeded, it becomesdifficult to correct field curvature fluctuations that occur duringzooming. Furthermore, the overall length of the zoom lens system isincreased, so that in order to collect a sufficient quantity of light,the effective diameter and weight of the first lens group G1 isincreased, which undesirably causes an increase in manufacturing costs.

If the lower limit of condition (13) or (14) is exceeded, althoughadvantageous for reducing the overall length of the zoom lens system, itbecomes difficult to correct fluctuations in field curvature that occurduring zooming.

By simultaneously satisfying conditions (13) and (14), the fluctuationsin field curvature that occur during zooming can be further suppressed.However, conditions (13) and (14) do not necessarily need to besimultaneously satisfied (conditions (13) and (14) are not integrallyinseparable), a zoom lens system satisfying one of conditions (13) and(14) can also exhibit the same effect to a certain degree, and can beincluded in the technical scope of the zoom lens system according to thepresent invention.

As described above, in the zoom lens system according to the secondaspect of the present invention, the first lens group G1 is configuredof the negative lens element 11 having a convex surface on the objectside, the negative lens element 12 having a convex surface on the objectside, the biconcave negative lens element 13 and the positive lenselement 14 having a convex surface on the object side, in that orderfrom the object side.

In the zoom lens system according to the second aspect of the presentinvention, favorably correcting distortion and lateral chromaticaberration that occur in the first lens group G1 is effective for thecorrection of distortion and lateral chromatic aberration in the entirezoom lens system. By forming a convex surface on the object side of eachof the negative lens element 11 and the negative lens element 12,occurrence of distortion can be suppressed. The spherical aberration,axial chromatic aberration, lateral chromatic aberration and fieldcurvature that occur in the first through third lens groups G1 throughG3 can be corrected by the positive lens element 14.

Condition (15) specifies the partial dispersion ratio at the g-line andat the F-line of the positive lens element 14 that is provided closestto the image side within the first lens group G1. By satisfyingcondition (15), axial chromatic aberration and lateral chromaticaberration, especially in the secondary spectrum, can be favorablycorrected.

If the upper limit of condition (15) is exceeded, the lateral chromaticaberration becomes overcorrected, and axial chromatic aberration at thelong focal length extremity in particular remains insufficientlycorrected.

If the lower limit of condition (15) is exceeded, the lateral chromaticaberration at the long focal length extremity becomes overcorrected.

Specific first through fifteenth numerical embodiments will be hereindiscussed. In the various aberration diagrams, lateral aberrationdiagrams and the tables, the d-line, g-line and C-line show aberrationsat their respective wave-lengths; S designates the sagittal image, Mdesignates the meridional image, Fno. designates the f-number, fdesignates the focal length of the entire optical system, W designatesthe half angle of view (°), Y designates the image height, fB designatesthe backfocus, L designates the overall length of the lens system, Rdesignates the radius of curvature, d designates the lens thickness ordistance between lenses, N(d) designates the refractive index at thed-line, and ν(d) designates the Abbe number with respect to the d-line.The unit used for the various lengths is defined in millimeters (mm).The values for the f-number, the focal length, the half angle-of-view,the image height, the backfocus, the overall length of the lens system,and the distance between lenses (which changes during zooming) are shownin the following order: short focal length extremity, intermediate focallength, and long focal length extremity.

An aspherical surface which is rotationally symmetrical about theoptical axis is defined as:

x=cy ²/(1+[1−{1+K}c ² y ²]^(1/2))+A4y ⁴ +A6y ⁶ +A8y ⁸ +A10y ¹⁰ +A12y ¹²

wherein ‘x’ designates a distance from a tangent plane of the asphericalvertex, ‘c’ designates the curvature (1/r) of the aspherical vertex, ‘y’designates the distance from the optical axis, ‘K’ designates the coniccoefficient, A4 designates a fourth-order aspherical coefficient, A6designates a sixth-order aspherical coefficient, A8 designates aneighth-order aspherical coefficient, A10 designates a tenth-orderaspherical coefficient, A12 designates a twelfth-order asphericalcoefficient, and ‘x’ designates the amount of sag.

Numerical Embodiment 1

FIGS. 1 through 10C and Tables 1 through 5 show a first numericalembodiment of the zoom lens system according to the present invention.FIG. 1 shows a lens arrangement of the first numerical embodiment of thezoom lens system, at the short focal length extremity when focused on anobject at infinity. FIGS. 2A, 2B, 2C and 2D show various aberrationsthat occurred in the lens arrangement shown in FIG. 1, at the shortfocal length extremity when focused on an object at infinity. FIGS. 3A,3B and 3C show lateral aberrations that occurred in the lens arrangementshown in FIG. 1, at the short focal length extremity when focused on anobject at infinity. FIGS. 4A, 4B, 4C and 4D show various aberrationsthat occurred in the lens arrangement shown in FIG. 1, at anintermediate focal length when focused on an object at infinity. FIGS.5A, 5B and 5C show lateral aberrations that occurred in the lensarrangement shown in FIG. 1, at an intermediate focal length whenfocused on an object at infinity. FIGS. 6A, 6B, 6C and 6D show variousaberrations that occurred in the lens arrangement shown in FIG. 1, atthe long focal length extremity when focused on an object at infinity.FIGS. 7A, 7B and 7C show lateral aberrations that occurred in the lensarrangement shown in FIG. 1, at the long focal length extremity whenfocused on an object at infinity. FIGS. 8A, 8B and 8C show lateralaberrations that occurred in the lens arrangement shown in FIG. 1 whenthe image-stabilizing lens group is decentered (during animage-stabilizing drive operation), at the short focal length extremitywhen focused on an object at infinity. FIGS. 9A, 9B and 9C show lateralaberrations that occurred in the lens arrangement shown in FIG. 1 whenthe image-stabilizing lens group is decentered (during animage-stabilizing drive operation), at an intermediate focal length whenfocused on an object at infinity. FIGS. 10A, 10B and 10C show lateralaberrations that occurred in the lens arrangement shown in FIG. 1 whenthe image-stabilizing lens group is decentered (during animage-stabilizing drive operation), at the long focal length extremitywhen focused on an object at infinity. Table 1 shows the lens surfacedata, Table 2 shows the aspherical surface data, Table 3 shows variouslens-system data, Table 4 shows image-stabilizing drive data, and Table5 shows lens group data.

The zoom lens system of the first numerical embodiment is configured ofa negative first lens group G1, a positive second lens group G2, anegative third lens group G3 and a positive fourth lens group G4, inthat order from the object side. A diaphragm S is provided between thesecond lens group G2 and the third lens group G3, and the diaphragm Smoves integrally with the second lens group G2.

The first lens group G1 is configured of a negative meniscus lenselement 11 having a convex surface on the object side, a negativemeniscus lens element 12 having a convex surface on the object side, abiconcave negative lens element 13, and a biconvex positive lens element14, in that order from the object side. The negative meniscus lenselement 11 is a hybrid lens formed by a glass lens element with anaspherical surface layer, formed from a synthetic resin material,adhered onto the image side thereof.

The second lens group G2 is configured of a positive meniscus lenselement 21 having a convex surface on the object side, a cemented lensformed by a negative meniscus lens element 22 having a convex surface onthe object side, and a biconvex positive lens element 23; and a biconvexpositive lens element 24, in that order from the object side.

The third lens group G3 is configured of a negative first sub-lens groupG3 a and a negative second sub-lens group G3 b, in that order from theobject side.

The second sub-lens group G3 b serves as an image-shake correction lensgroup (image-stabilizing lens group) which corrects image shake that iscaused by hand shake/vibrations, etc., by moving (decentering) theimage-shake correction lens group in a direction orthogonal to theoptical axis to thereby change the imaging position.

The first sub-lens group G3 a is configured of a cemented lens formed bya biconcave negative lens element 31 and a biconvex positive lenselement 32, in that order from the object side.

The second sub-lens group G3 b is configured of a biconcave negativelens element (a negative single lens element having a concave surface onthe image side) 33 and a positive meniscus lens element 34 having convexsurface on the object side (a positive single lens element having aconvex surface on the object side), in that order from the object side,and an air lens having a meniscus shape with a convex surface on theobject side is formed between the biconcave negative lens element 33 andthe positive meniscus lens element 34.

The fourth lens group G4 is configured of a cemented lens provided witha biconvex positive lens element 41, a biconcave negative lens element42 and a biconvex positive lens element 43; and a cemented lens providedwith a biconcave negative lens element 44 and a biconvex positive lenselement 45, in that order from the object side. The biconcave negativelens element 44 is a hybrid lens formed by a glass lens element with anaspherical surface layer, formed from a synthetic resin material,adhered onto the object side thereof.

TABLE 1 LENS SURFACE DATA Surf. No. R d N(d) ν(d)  1 70.143 2.6801.75500 52.3  2 27.200 0.280 1.52972 42.7  3* 23.398 9.810  4 94.1521.650 1.72916 54.7  5 33.886 8.630  6 −111.219 2.000 1.61800 63.4  746.602 6.050  8 53.980 7.500 1.59551 39.2  9 −137.448 d9  10 49.6453.980 1.57501 41.5 11 193.560 1.820 12 89.353 1.500 1.80610 33.3 1328.082 7.080 1.51633 64.1 14 −120.510 5.863 15 90.623 3.400 1.48749 70.216 −144.997 1.730 17 (Diaphragm) ∞ d17 18 −137.164 1.500 1.81600 46.6 1932.237 4.120 1.68893 31.1 20 −163.680 1.640 21 −131.661 1.500 1.8340037.2 22 713.414 0.300 23 77.167 1.670 1.54814 45.8 24 92.600 d24 2534.439 5.590 1.80000 29.9 26 −5000.000 1.500 1.80100 35.0 27 21.95011.540  1.49700 81.6 28 −58.800 0.750 29* −3241.071 0.200 1.52972 42.730 −3241.071 1.500 1.83400 37.2 31 33.728 7.980 1.48749 70.2 32 −77.015— The asterisk (*) designates an aspherical surface which isrotationally symmetrical with respect to the optical axis.

TABLE 2 ASPHERICAL SURFACE DATA Surf. No. K A4 A6 A8 A10 3 −1.0000.3017E−05 −0.1883E−09 0.1208E−11 −0.3174E−14 29 0.000 −0.3441E−050.1181E−08 −0.3217E−11 0.3495E−13

TABLE 3 VARIOUS LENS-SYSTEM DATA Zoom Ratio: 1.53 Short Focal LengthIntermediate Long Focal Length Extremity Focal Length Extremity FNO. 4.64.6 4.6 f 28.70 35.00 43.87 W 45.3 38.8 32.2 Y 27.80 27.80 27.80 fB66.64 74.50 83.99 L 222.72 218.85 219.26 d9 24.418 15.585 8.631 d174.730 9.698 17.061 d24 23.162 15.301 5.816

TABLE 4 IMAGE-STABILIZING DRIVE DATA Short Focal Length Extremity LensMovement Amount 0.30 Image Movement Amount −0.15 Correction Angle 0.30Intermediate Focal Length Lens Movement Amount 0.33 Image MovementAmount −0.18 Correction Angle 0.30 Long Focal Length Extremity LensMovement Amount 0.37 Image Movement Amount −0.23 Correction Angle 0.30

TABLE 5 LENS GROUP DATA Lens Group 1^(st) Surface Focal Length 1 1−29.26 2 10 53.52 3 18 −82.15 4 25 71.59

Numerical Embodiment 2

FIGS. 11 through 20C and Tables 6 through 10 show a second numericalembodiment of the zoom lens system according to the present invention.FIG. 11 shows a lens arrangement of the second numerical embodiment ofthe zoom lens system, at the short focal length extremity when focusedon an object at infinity. FIGS. 12A, 12B, 12C and 12D show variousaberrations that occurred in the lens arrangement shown in FIG. 11, atthe short focal length extremity when focused on an object at infinity.FIGS. 13A, 13B and 13C show lateral aberrations that occurred in thelens arrangement shown in FIG. 11, at the short focal length extremitywhen focused on an object at infinity. FIGS. 14A, 14B, 14C and 14D showvarious aberrations that occurred in the lens arrangement shown in FIG.11, at an intermediate focal length when focused on an object atinfinity. FIGS. 15A, 15B and 15C show lateral aberrations that occurredin the lens arrangement shown in FIG. 11, at an intermediate focallength when focused on an object at infinity. FIGS. 16A, 16B, 16C and16D show various aberrations that occurred in the lens arrangement shownin FIG. 11, at the long focal length extremity when focused on an objectat infinity. FIGS. 17A, 17B and 17C show lateral aberrations thatoccurred in the lens arrangement shown in FIG. 11, at the long focallength extremity when focused on an object at infinity. FIGS. 18A, 18Band 18C show lateral aberrations that occurred in the lens arrangementshown in FIG. 11 when the image-stabilizing lens group is decentered(during an image-stabilizing drive operation), at the short focal lengthextremity when focused on an object at infinity. FIGS. 19A, 19B and 19Cshow lateral aberrations that occurred in the lens arrangement shown inFIG. 11 when the image-stabilizing lens group is decentered (during animage-stabilizing drive operation), at an intermediate focal length whenfocused on an object at infinity. FIGS. 20A, 20B and 20C show lateralaberrations that occurred in the lens arrangement shown in FIG. 11 whenthe image-stabilizing lens group is decentered (during animage-stabilizing drive operation), at the long focal length extremitywhen focused on an object at infinity. Table 6 shows the lens surfacedata, Table 7 shows the aspherical surface data, Table 8 shows variouslens-system data, Table 9 shows image-stabilizing drive data, and Table10 shows lens group data.

The fundamental lens arrangement of the second numerical embodiment isthe same as that of the first numerical embodiment.

TABLE 6 LENS SURFACE DATA Surf. No. R d N(d) ν(d)  1 69.831 3.1201.78590 44.2  2 27.200 0.200 1.52972 42.7  3* 22.911 8.050  4 52.3441.650 1.75500 52.3  5 29.769 9.280  6 −72.757 2.000 1.61800 63.4  745.461 5.290  8 52.269 8.640 1.56732 42.8  9 −95.077 d9  10 53.398 3.4001.54814 45.8 11 125.856 2.340 12 104.138 1.500 1.80000 29.9 13 28.6846.980 1.58144 40.7 14 −153.716 6.340 15 78.510 3.670 1.49700 81.6 16−125.616 1.610 17 (Diaphragm) ∞ d17 18 −111.884 1.500 1.83481 42.7 1932.327 4.290 1.68893 31.1 20 −124.154 1.080 21 −1204.327 1.500 1.8502632.3 22 139.318 0.370 23 56.411 1.770 1.80518 25.4 24 67.230 d24 2535.945 6.200 1.80100 35.0 26 −1000.000 1.500 1.83400 37.2 27 23.04711.480  1.49700 81.6 28 −53.099 0.750 29* −3272.914 0.200 1.52972 42.730 −3272.914 1.500 1.83400 37.2 31 37.277 7.310 1.48749 70.2 32 −94.390— The asterisk (*) designates an aspherical surface which isrotationally symmetrical with respect to the optical axis.

TABLE 7 ASPHERICAL SURFACE DATA Surf. No. K A4 A6 A8 A10 3 −1.0000.2447E−05 −0.3260E−09 −0.1948E−12 −0.1958E−14 29 0.000 −0.3209E−050.2326E−09 0.2241E−12 0.2444E−13

TABLE 8 VARIOUS LENS-SYSTEM DATA Zoom Ratio: 1.53 Short Long FocalLength Intermediate Focal Length Extremity Focal Length Extremity FNO.4.6 4.6 4.6 f 28.70 35.00 43.87 W 45.3 38.8 32.3 Y 27.80 27.80 27.80 fB65.85 73.70 83.45 L 222.79 218.27 217.87 d9 25.085 15.485 7.751 d174.920 10.001 17.329 d24 23.413 15.564 5.816

TABLE 9 IMAGE-STABILIZING DRIVE DATA Short Focal Length Extremity LensMovement Amount 0.42 Image Movement Amount −0.15 Correction Angle 0.30Intermediate Focal Length Lens Movement Amount 0.47 Image MovementAmount −0.18 Correction Angle 0.30 Long Focal Length Extremity LensMovement Amount 0.52 Image Movement Amount −0.23 Correction Angle 0.30

TABLE 10 LENS GROUP DATA Lens Group 1^(st) Surface Focal Length 1 1−29.97 2 10 54.37 3 18 −91.34 4 25 76.53

Numerical Embodiment 3

FIGS. 21 through 30C and Tables 11 through 15 show a third numericalembodiment of the zoom lens system according to the present invention.FIG. 21 shows a lens arrangement of the third numerical embodiment ofthe zoom lens system, at the short focal length extremity when focusedon an object at infinity. FIGS. 22A, 22B, 22C and 22D show variousaberrations that occurred in the lens arrangement shown in FIG. 21, atthe short focal length extremity when focused on an object at infinity.FIGS. 23A, 23B and 23C show lateral aberrations that occurred in thelens arrangement shown in FIG. 21, at the short focal length extremitywhen focused on an object at infinity. FIGS. 24A, 24B, 24C and 24D showvarious aberrations that occurred in the lens arrangement shown in FIG.21, at an intermediate focal length when focused on an object atinfinity. FIGS. 25A, 25B and 25C show lateral aberrations that occurredin the lens arrangement shown in FIG. 21, at an intermediate focallength when focused on an object at infinity. FIGS. 26A, 26B, 26C and26D show various aberrations that occurred in the lens arrangement shownin FIG. 21, at the long focal length extremity when focused on an objectat infinity. FIGS. 27A, 27B and 27C show lateral aberrations thatoccurred in the lens arrangement shown in FIG. 21, at the long focallength extremity when focused on an object at infinity. FIGS. 28A, 28Band 28C show lateral aberrations that occurred in the lens arrangementshown in FIG. 21 when the image-stabilizing lens group is decentered(during an image-stabilizing drive operation), at the short focal lengthextremity when focused on an object at infinity. FIGS. 29A, 29B and 29Cshow lateral aberrations that occurred in the lens arrangement shown inFIG. 21 when the image-stabilizing lens group is decentered (during animage-stabilizing drive operation), at an intermediate focal length whenfocused on an object at infinity. FIGS. 30A, 30B and 30C show lateralaberrations that occurred in the lens arrangement shown in FIG. 21 whenthe image-stabilizing lens group is decentered (during animage-stabilizing drive operation), at the long focal length extremitywhen focused on an object at infinity. Table 11 shows the lens surfacedata, Table 12 shows the aspherical surface data, Table 13 shows variouslens-system data, Table 14 shows image-stabilizing drive data, and Table15 shows lens group data.

The fundamental lens arrangement of the third numerical embodiment isthe same as that of the first numerical embodiment except for thefollowing feature:

(1) The negative single lens element (negative single lens elementhaving a concave surface on the image side) 33 of the second sub-lensgroup G3 b is a negative meniscus lens element having a convex surfaceon the object side.

TABLE 11 LENS SURFACE DATA Surf. No. R d N (d) ν (d)  1 65.846 2.1601.80610 40.9  2 27.341 0.200 1.52972 42.7  3* 23.079 7.840  4 52.1601.650 1.74100 52.7  5 29.806 10.810   6 −77.937 1.900 1.64000 60.1  748.710 5.650  8 55.331 9.120 1.59551 39.2  9 −109.115 d9 10 51.629 4.7701.53172 48.9 11 182.790 2.150 12 101.662 1.500 1.80000 29.9 13 27.2187.340 1.58144 40.7 14 −137.754 6.226 15 86.979 3.440 1.49700 81.6 16−148.336 1.740 17 (Diaphragm) ∞ d17 18 −96.136 1.500 1.83481 42.7 1936.406 3.980 1.69895 30.1 20 −128.522 1.080 21 4320.238 1.500 1.8340037.2 22 114.364 0.580 23 63.061 1.770 1.79504 28.7 24 81.995 d24 2542.173 5.000 1.80440 39.6 26 −1000.000 1.500 1.80610 40.9 27 26.07010.840  1.49700 81.6 28 −54.507 0.750 29* −1623.804 0.200 1.52972 42.730 −1623.804 1.500 1.83400 37.2 31 37.653 7.430 1.49700 81.6 32 −83.132— The asterisk (*) designates an aspherical surface which isrotationally symmetrical with respect to the optical axis.

TABLE 12 ASPHERICAL SURFACE DATA Surf. No. K A4 A6 A8 A10 3 −1.0000.2674E−05 −0.4322E−09 0.7364E−12 −0.2496E−14 29 0.000 −0.2701E−050.5859E−09 −0.4420E−12 0.1221E−13

TABLE 13 VARIOUS LENS-SYSTEM DATA Zoom Ratio: 1.56 Short Long FocalLength Intermediate Focal Length Extremity Focal Length Extremity FNO.4.6 4.6 4.6 f 28.70 35.00 44.66 W 45.3 38.8 31.8 Y 27.80 27.80 27.80 fB66.13 73.78 86.00 L 221.68 217.39 217.96 d9 25.639 15.262 5.791 d174.920 10.014 16.224 d24 20.866 14.202 5.816

TABLE 14 IMAGE-STABILIZING DRIVE DATA Short Focal Length Extremity LensMovement Amount 0.45 Image Movement Amount −0.15 Correction Angle 0.30Intermediate Focal Length Lens Movement Amount 0.51 Image MovementAmount −0.18 Correction Angle 0.30 Long Focal Length Extremity LensMovement Amount 0.58 Image Movement Amount −0.23 Correction Angle 0.30

TABLE 15 LENS GROUP DATA Lens Group 1^(st) Surface Focal Length 1 1−30.51 2 10 53.49 3 18 −89.40 4 25 78.14

Numerical Embodiment 4

FIGS. 31 through 40C and Tables 16 through 20 show a fourth numericalembodiment of the zoom lens system according to the present invention.FIG. 31 shows a lens arrangement of the fourth numerical embodiment ofthe zoom lens system, at the short focal length extremity when focusedon an object at infinity. FIGS. 32A, 32B, 32C and 32D show variousaberrations that occurred in the lens arrangement shown in FIG. 31, atthe short focal length extremity when focused on an object at infinity.FIGS. 33A, 33B and 33C show lateral aberrations that occurred in thelens arrangement shown in FIG. 31, at the short focal length extremitywhen focused on an object at infinity. FIGS. 34A, 34B, 34C and 34D showvarious aberrations that occurred in the lens arrangement shown in FIG.31, at an intermediate focal length when focused on an object atinfinity. FIGS. 35A, 35B and 35C show lateral aberrations that occurredin the lens arrangement shown in FIG. 31, at an intermediate focallength when focused on an object at infinity. FIGS. 36A, 36B, 36C and36D show various aberrations that occurred in the lens arrangement shownin FIG. 31, at the long focal length extremity when focused on an objectat infinity. FIGS. 37A, 37B and 37C show lateral aberrations thatoccurred in the lens arrangement shown in FIG. 31, at the long focallength extremity when focused on an object at infinity. FIGS. 38A, 38Band 38C show lateral aberrations that occurred in the lens arrangementshown in FIG. 31 when the image-stabilizing lens group is decentered(during an image-stabilizing drive operation), at the short focal lengthextremity when focused on an object at infinity. FIGS. 39A, 39B and 39Cshow lateral aberrations that occurred in the lens arrangement shown inFIG. 31 when the image-stabilizing lens group is decentered (during animage-stabilizing drive operation), at an intermediate focal length whenfocused on an object at infinity. FIGS. 40A, 40B and 40C show lateralaberrations that occurred in the lens arrangement shown in FIG. 31 whenthe image-stabilizing lens group is decentered (during animage-stabilizing drive operation), at the long focal length extremitywhen focused on an object at infinity. Table 16 shows the lens surfacedata, Table 17 shows the aspherical surface data, Table 18 shows variouslens-system data, Table 19 shows image-stabilizing drive data, and Table20 shows lens group data.

The fundamental lens arrangement of the fourth numerical embodiment isthe same as that of the first numerical embodiment except for thefollowing feature:

(1) In the fourth lens group G4, the positive lens element 41 is aplanoconvex positive lens element having a convex surface on the objectside, and the negative lens element 42 is a planoconcave lens elementhaving a concave surface on the image side.

TABLE 16 LENS SURFACE DATA Surf. No. R d N (d) ν (d)  1 67.231 3.0001.81600 46.6  2 25.667 0.200 1.52972 42.7  3* 21.526 9.050  4 61.7141.650 1.72916 54.7  5 35.265 9.010  6 −73.925 1.650 1.61800 63.4  745.555 5.350  8 55.892 9.670 1.61340 44.3  9 −107.223 d9 10 67.588 3.2901.59270 35.3 11 210.129 2.180 12 133.613 1.500 1.80000 29.9 13 30.6536.610 1.59551 39.2 14 −170.797 6.487 15 60.717 4.200 1.43875 95.0 16−113.763 1.450 17 (Diaphragm) ∞ d17 18 −153.492 1.500 1.81600 46.6 1930.409 4.840 1.65412 39.7 20 −85.686 0.830 21 −146.449 1.500 1.8340037.2 22 88.637 0.840 23 72.008 2.180 1.80518 25.4 24 218.003 d24 2533.784 6.300 1.76200 40.1 26 ∞ 1.500 1.83481 42.7 27 22.070 11.680 1.49700 81.6 28 −54.280 0.750 29* −4942.873 0.300 1.52972 42.7 30−4942.873 1.500 1.83400 37.2 31 37.317 7.170 1.48749 70.2 32 −102.018 —The asterisk (*) designates an aspherical surface which is rotationallysymmetrical with respect to the optical axis.

TABLE 17 ASPHERICAL SURFACE DATA Surf. No. K A4 A6 A8 A10 3 −1.0000.3705E−05 −0.3363E−09 0.2667E−11 −0.5605E−14 29 0.000 −0.3038E−050.1496E−08 −0.4796E−11 0.4379E−13

TABLE 18 VARIOUS LENS-SYSTEM DATA Zoom Ratio: 1.53 Short Focal LengthIntermediate Long Focal Length Extremity Focal Length Extremity FNO. 4.64.6 4.6 f 28.70 35.00 43.87 W 45.3 39.0 32.4 Y 27.80 27.80 27.80 fB67.86 76.60 87.13 L 229.34 223.75 222.47 d9 25.017 15.078 7.178 d174.760 9.110 15.727 d24 25.512 16.772 6.242

TABLE 19 IMAGE-STABILIZING DRIVE DATA Short Focal Length Extremity LensMovement Amount 0.24 Image Movement Amount −0.15 Correction Angle 0.30Intermediate Focal Length Lens Movement Amount 0.26 Image MovementAmount −0.18 Correction Angle 0.30 Long Focal Length Extremity LensMovement Amount 0.30 Image Movement Amount −0.23 Correction Angle 0.30

TABLE 19 IMAGE-STABILIZING DRIVE DATA Short Focal Length Extremity LensMovement Amount 0.24 Image Movement Amount −0.15 Correction Angle 0.30Intermediate Focal Length Lens Movement Amount 0.26 Image MovementAmount −0.18 Correction Angle 0.30 Long Focal Length Extremity LensMovement Amount 0.30 Image Movement Amount −0.23 Correction Angle 0.30

Numerical Embodiment 5

FIGS. 41 through 50C and Tables 21 through 25 show a fifth numericalembodiment of the zoom lens system according to the present invention.FIG. 41 shows a lens arrangement of the fifth numerical embodiment ofthe zoom lens system, at the short focal length extremity when focusedon an object at infinity. FIGS. 42A, 42B, 42C and 42D show variousaberrations that occurred in the lens arrangement shown in FIG. 41, atthe short focal length extremity when focused on an object at infinity.FIGS. 43A, 43B and 43C show lateral aberrations that occurred in thelens arrangement shown in FIG. 41, at the short focal length extremitywhen focused on an object at infinity. FIGS. 44A, 44B, 44C and 44D showvarious aberrations that occurred in the lens arrangement shown in FIG.41, at an intermediate focal length when focused on an object atinfinity. FIGS. 45A, 45B and 45C show lateral aberrations that occurredin the lens arrangement shown in FIG. 41, at an intermediate focallength when focused on an object at infinity. FIGS. 46A, 46B, 46C and46D show various aberrations that occurred in the lens arrangement shownin FIG. 41, at the long focal length extremity when focused on an objectat infinity. FIGS. 47A, 47B and 47C show lateral aberrations thatoccurred in the lens arrangement shown in FIG. 41, at the long focallength extremity when focused on an object at infinity. FIGS. 48A, 48Band 48C show lateral aberrations that occurred in the lens arrangementshown in FIG. 41 when the image-stabilizing lens group is decentered(during an image-stabilizing drive operation), at the short focal lengthextremity when focused on an object at infinity. FIGS. 49A, 49B and 49Cshow lateral aberrations that occurred in the lens arrangement shown inFIG. 41 when the image-stabilizing lens group is decentered (during animage-stabilizing drive operation), at an intermediate focal length whenfocused on an object at infinity. FIGS. 50A, 50B and 50C show lateralaberrations that occurred in the lens arrangement shown in FIG. 41 whenthe image-stabilizing lens group is decentered (during animage-stabilizing drive operation), at the long focal length extremitywhen focused on an object at infinity. Table 21 shows the lens surfacedata, Table 22 shows the aspherical surface data, Table 23 shows variouslens-system data, Table 24 shows image-stabilizing drive data, and Table25 shows lens group data.

The fundamental lens arrangement of the fifth numerical embodiment isthe same as that of the fourth numerical embodiment.

TABLE 21 LENS SURFACE DATA Surf. No. R d N (d) ν (d)  1 69.640 2.0501.77250 49.6  2 27.201 0.200 1.52972 42.7  3* 23.035 9.700  4 66.8451.950 1.72916 54.7  5 32.191 8.670  6 −87.917 2.330 1.61800 63.4  746.539 5.240  8 53.814 8.950 1.61340 44.3  9 −122.685 d9 10 56.394 3.4801.58144 40.7 11 177.940 2.360 12 140.867 1.500 1.80000 29.9 13 28.6946.660 1.59551 39.2 14 −173.644 6.545 15 72.548 3.820 1.49700 81.6 16−116.078 1.570 17 (Diaphragm) ∞ d17 18 −84.818 1.500 1.81600 46.6 1935.711 4.600 1.65412 39.7 20 −67.461 0.960 21 −159.881 1.500 1.8340037.2 22 71.757 0.940 23 66.173 2.360 1.80518 25.4 24 387.509 d24 2534.203 5.600 1.80610 40.9 26 ∞ 1.530 1.83481 42.7 27 22.017 11.650 1.49700 81.6 28 −55.216 1.210 29* −3234.831 0.300 1.52972 42.7 30−3234.831 2.550 1.83400 37.2 31 34.948 7.350 1.48749 70.2 32 −100.886 —The asterisk (*) designates an aspherical surface which is rotationallysymmetrical with respect to the optical axis.

TABLE 22 ASPHERICAL SURFACE DATA Surf. No. K A4 A6 A8 A10 3 −1.0000.2965E−05 −0.1833E−09 0.9625E−12 −0.2739E−14 29 0.000 −0.3186E−050.1201E−08 −0.2848E−11 0.3902E−13

TABLE 23 VARIOUS LENS-SYSTEM DATA Zoom Ratio: 1.53 Short Focal LengthIntermediate Long Focal Length Extremity Focal Length Extremity FNO. 4.64.6 4.6 f 28.70 35.00 43.88 W 45.3 38.9 32.3 Y 27.80 27.80 27.80 fB66.07 74.13 84.10 L 226.87 221.82 220.84 d9 24.743 14.965 7.088 d175.032 9.756 16.650 d24 23.954 15.895 5.930

TABLE 24 IMAGE-STABILIZING DRIVE DATA Short Focal Length Extremity LensMovement Amount 0.27 Image Movement Amount −0.15 Correction Angle 0.30Intermediate Focal Length Lens Movement Amount 0.31 Image MovementAmount −0.18 Correction Angle 0.30 Long Focal Length Extremity LensMovement Amount 0.34 Image Movement Amount −0.23 Correction Angle 0.30

TABLE 25 LENS GROUP DATA Lens Group 1^(st) Surface Focal Length 1 1−30.04 2 10 54.15 3 18 −91.26 4 25 78.60

Numerical Embodiment 6

FIGS. 51 through 60C and Tables 26 through 30 show a sixth numericalembodiment of the zoom lens system according to the present invention.FIG. 51 shows a lens arrangement of the sixth numerical embodiment ofthe zoom lens system, at the short focal length extremity when focusedon an object at infinity. FIGS. 52A, 52B, 52C and 52D show variousaberrations that occurred in the lens arrangement shown in FIG. 51, atthe short focal length extremity when focused on an object at infinity.FIGS. 53A, 53B and 53C show lateral aberrations that occurred in thelens arrangement shown in FIG. 51, at the short focal length extremitywhen focused on an object at infinity. FIGS. 54A, 54B, 54C and 54D showvarious aberrations that occurred in the lens arrangement shown in FIG.51, at an intermediate focal length when focused on an object atinfinity. FIGS. 55A, 55B and 55C show lateral aberrations that occurredin the lens arrangement shown in FIG. 51, at an intermediate focallength when focused on an object at infinity. FIGS. 56A, 56B, 56C and56D show various aberrations that occurred in the lens arrangement shownin FIG. 51, at the long focal length extremity when focused on an objectat infinity. FIGS. 57A, 57B and 57C show lateral aberrations thatoccurred in the lens arrangement shown in FIG. 51, at the long focallength extremity when focused on an object at infinity. FIGS. 58A, 58Band 58C show lateral aberrations that occurred in the lens arrangementshown in FIG. 51 when the image-stabilizing lens group is decentered(during an image-stabilizing drive operation), at the short focal lengthextremity when focused on an object at infinity. FIGS. 59A, 59B and 59Cshow lateral aberrations that occurred in the lens arrangement shown inFIG. 51 when the image-stabilizing lens group is decentered (during animage-stabilizing drive operation), at an intermediate focal length whenfocused on an object at infinity. FIGS. 60A, 60B and 60C show lateralaberrations that occurred in the lens arrangement shown in FIG. 51 whenthe image-stabilizing lens group is decentered (during animage-stabilizing drive operation), at the long focal length extremitywhen focused on an object at infinity. Table 26 shows the lens surfacedata, Table 27 shows the aspherical surface data, Table 28 shows variouslens-system data, Table 29 shows image-stabilizing drive data, and Table30 shows lens group data.

The fundamental lens arrangement of the sixth numerical embodiment isthe same as that of the first numerical embodiment except for thefollowing features:

(1) The positive single lens element (a positive single lens elementhaving a convex surface on the object side) 34 of the second sub-lensgroup G3 b is a biconvex positive lens element.

(2) In the fourth lens group G4, the positive lens element 41 is aplanoconvex positive lens element having a convex surface on the objectside, and the negative lens element 42 is a planoconcave negative lenselement having a concave surface on the image side.

TABLE 26 LENS SURFACE DATA Surf. No. R d N(d) ν(d)  1 69.709 2.0501.81600 46.6  2 27.200 0.200 1.52972 42.7  3* 23.155 11.240   4 80.0811.650 1.72916 54.7  5 34.215 9.200  6 −98.912 1.650 1.61800 63.4  750.268 4.760  8 53.858 8.750 1.61340 44.3  9 −139.418 d9  10 56.7204.150 1.54814 45.8 11 416.325 3.230 12 125.462 1.500 1.80000 29.9 1327.385 6.790 1.60342 38.0 14 −198.527 5.968 15 77.525 3.680 1.49700 81.616 −124.041 1.640 17 (Diaphragm) ∞ d17 18 −184.268 1.500 1.83481 42.7 1935.239 3.640 1.68893 31.1 20 −726.166 1.670 21 −140.451 1.500 1.7380032.3 22 92.902 1.050 23 99.582 2.410 1.80518 25.4 24 −571.932 d24 2533.853 5.620 1.79952 42.2 26 ∞ 1.500 1.83481 42.7 27 21.985 11.550 1.49700 81.6 28 −56.304 0.750 29* −1045.712 0.200 1.52972 42.7 30−1045.712 1.500 1.83400 37.2 31 35.798 7.540 1.48749 70.2 32 −86.473 —The asterisk (*) designates an aspherical surface which is rotationallysymmetrical with respect to the optical axis.

TABLE 27 ASPHERICAL SURFACE DATA Surf. No. K A4 A6 A8 A10 3 −1.0000.2945E−05 0.5941E−09 −0.7814E−13 −0.1062E−14 29 0.000 −0.3313E−050.8377E−09 0.6548E−12 0.2894E−13

TABLE 28 VARIOUS LENS-SYSTEM DATA Zoom Ratio: 1.53 Short Focal LengthIntermediate Long Focal Length Extremity Focal Length Extremity FNO. 4.64.6 4.6 f 28.70 35.00 43.87 W 45.3 38.9 32.3 Y 27.80 27.80 27.80 fB65.85 74.18 84.16 L 224.65 219.91 219.49 d9 23.113 13.673 6.142 d174.670 9.374 16.484 d24 24.124 15.796 5.820

TABLE 29 IMAGE-STABILIZING DRIVE DATA Short Focal Length Extremity LensMovement Amount 0.52 Image Movement Amount −0.15 Correction Angle 0.30Intermediate Focal Length Lens Movement Amount 0.59 Image MovementAmount −0.18 Correction Angle 0.30 Long Focal Length Extremity LensMovement Amount 0.66 Image Movement Amount −0.23 Correction Angle 0.30

TABLE 30 LENS GROUP DATA Lens Group 1^(st) Surface Focal Length 1 1−28.94 2 10 52.51 3 18 −88.53 4 25 77.64

Numerical Embodiment 7

FIGS. 61 through 67C and Tables 31 through 34 show a seventh numericalembodiment of the zoom lens system according to the present invention.FIG. 61 shows a lens arrangement of the seventh numerical embodiment ofthe zoom lens system, at the short focal length extremity when focusedon an object at infinity. FIGS. 62A, 62B, 62C and 62D show variousaberrations that occurred in the lens arrangement shown in FIG. 61, atthe short focal length extremity when focused on an object at infinity.FIGS. 63A, 63B and 63C show lateral aberrations that occurred in thelens arrangement shown in FIG. 61, at the short focal length extremitywhen focused on an object at infinity. FIGS. 64A, 64B, 64C and 64D showvarious aberrations that occurred in the lens arrangement shown in FIG.61, at an intermediate focal length when focused on an object atinfinity. FIGS. 65A, 65B and 65C show lateral aberrations that occurredin the lens arrangement shown in FIG. 61, at an intermediate focallength when focused on an object at infinity. FIGS. 66A, 66B, 66C and66D show various aberrations that occurred in the lens arrangement shownin FIG. 61, at the long focal length extremity when focused on an objectat infinity. FIGS. 67A, 67B and 67C show lateral aberrations thatoccurred in the lens arrangement shown in FIG. 61, at the long focallength extremity when focused on an object at infinity. Table 31 showsthe lens surface data, Table 32 shows the aspherical surface data, Table33 shows various lens-system data, and Table 34 shows lens group data.

The zoom lens system of the seventh numerical embodiment is configuredof a negative first lens group G1, a positive second lens group G2, anegative third lens group G3, and a positive fourth lens group G4, inthat order from the object side. A diaphragm S is provided in betweenthe second lens group G2 and the third lens group G3. The diaphragm Smoves integrally with the second lens group G2.

The first lens group G1 is configured of a negative meniscus lenselement 11 having a convex surface on the object side (a negative lenselement having a convex surface on the object side), a negative meniscuslens element 12 having a convex surface on the object side (a negativelens element having a convex surface on the object side), a biconcavenegative lens element 13 and a biconvex positive lens element (apositive lens element having a convex surface on the object side) 14, inthat order from the object side. The negative meniscus lens element 11is a hybrid lens formed by a glass lens element with an asphericalsurface layer, formed from a synthetic resin material, adhered onto theimage side thereof.

The second lens group G2 is configured of a positive first sub-lensgroup G2 a and a positive second sub-lens group G2 b, in that order fromthe object side. The first sub-lens group G2 a is a focusing lens groupwhich moves in the optical axis direction (toward the image side) duringa focusing operation.

The first sub-lens group G2 a is configured of a positive meniscus lenselement (positive lens element having a convex surface on the objectside) 21 having a convex surface on the object side, and a cemented lensprovided with a negative meniscus lens element 22 having a convexsurface on the object side (a negative lens element having a convexsurface on the object side), and a biconvex positive lens element 23, inthat order from the object side.

The second sub-lens group G2 b is configured of a biconvex positive lenselement 24.

The third lens group G3 is configured of a cemented lens provided with abiconcave negative lens element 31 and a biconvex positive lens element32; a biconcave negative lens element 33 and a positive meniscus lenselement 34 having a convex surface on the object side, in that orderfrom the object side.

The fourth lens group G4 is configured of a positive third sub-lensgroup G4 a and a negative fourth sub-lens group G4 b, in that order fromthe object side.

The third sub-lens group G4 a is configured of a cemented lens providedwith a biconvex positive lens element (a positive lens element having aconvex surface on the object side) 41, a biconcave negative lens element42 and a biconvex positive lens element 43, in that order from theobject side.

The fourth sub-lens group G4 b is configured of a cemented lens having abiconcave negative lens element 44 and a biconvex positive lens element45, in that order from the object side. The biconcave negative lenselement 44 is a hybrid lens formed by a glass lens element with anaspherical surface layer, formed from a synthetic resin material,adhered onto the object side thereof.

TABLE 31 LENS SURFACE DATA Surf. No. R d N(d) ν(d)  1 67.727 2.4501.77250 49.6  2 27.200 0.220 1.52972 42.7  3* 23.089 7.830  4 51.9241.650 1.78800 47.4  5 29.458 9.410  6 −81.490 2.200 1.60300 65.5  748.108 5.890  8 53.263 8.830 1.56732 42.8  9 −124.700 d9  10 53.6673.820 1.56732 42.8 11 233.446 2.180 12 136.379 1.500 1.80000 29.9 1328.377 6.770 1.58144 40.7 14 −144.954 6.288 15 80.815 3.550 1.49700 81.616 −129.303 1.680 17 (Diaphragm) ∞ d17 18 −105.215 1.500 1.83481 42.7 1929.032 4.520 1.72047 34.7 20 −104.092 1.270 21 −185.193 1.500 1.8340037.2 22 79.688 0.830 23 65.796 2.170 1.80518 25.4 24 191.711 d24 2535.493 5.480 1.83400 37.2 26 −5000.000 1.500 1.80440 39.6 27 21.95011.710  1.49700 81.6 28 −55.545 0.860 29* −3241.954 0.200 1.52972 42.730 −3241.954 1.500 1.83400 37.2 31 34.353 7.590 1.48749 70.2 32 −95.291— The asterisk (*) designates an aspherical surface which isrotationally symmetrical with respect to the optical axis.

TABLE 32 ASPHERICAL SURFACE DATA Surf. No. K A4 A6 A8 A10 3 −1.0000.2782E−05 −0.1128E−09 0.2056E−12 −0.1990E−14 29 0.000 −0.3454E−050.9235E−09 −0.1297E−11 0.3435E−13

TABLE 33 VARIOUS LENS-SYSTEM DATA Zoom Ratio: 1.53 Short Focal LengthIntermediate Long Focal Length Extremity Focal Length Extremity FNO. 4.64.6 4.6 f 28.70 35.00 43.87 W 45.2 38.8 32.2 Y 27.80 27.80 27.80 fB65.91 73.50 82.88 L 222.37 218.13 217.99 d9 23.915 14.684 7.308 d174.860 9.856 17.084 d24 22.782 15.198 5.820

TABLE 34 LENS GROUP DATA Lens Group 1^(st) Surface Focal Length 1 1−30.12 2 10 53.78 3 18 −84.25 4 25 72.81

Numerical Embodiment 8

FIGS. 68 through 74C and Tables 35 through 38 show an eighth numericalembodiment of the zoom lens system according to the present invention.FIG. 68 shows a lens arrangement of the eighth numerical embodiment ofthe zoom lens system, at the short focal length extremity when focusedon an object at infinity. FIGS. 69A, 69B, 69C and 69D show variousaberrations that occurred in the lens arrangement shown in FIG. 68, atthe short focal length extremity when focused on an object at infinity.FIGS. 70A, 70B and 70C show lateral aberrations that occurred in thelens arrangement shown in FIG. 68, at the short focal length extremitywhen focused on an object at infinity. FIGS. 71A, 71B, 71C and 71D showvarious aberrations that occurred in the lens arrangement shown in FIG.68, at an intermediate focal length when focused on an object atinfinity. FIGS. 72A, 72B and 72C show lateral aberrations that occurredin the lens arrangement shown in FIG. 68, at an intermediate focallength when focused on an object at infinity. FIGS. 73A, 73B, 73C and73D show various aberrations that occurred in the lens arrangement shownin FIG. 68, at the long focal length extremity when focused on an objectat infinity. FIGS. 74A, 74B and 74C show lateral aberrations thatoccurred in the lens arrangement shown in FIG. 68, at the long focallength extremity when focused on an object at infinity. Table 35 showsthe lens surface data, Table 36 shows the aspherical surface data, Table37 shows various lens-system data, and Table 38 shows lens group data.

The fundamental lens arrangement of the eighth numerical embodiment isthe same as that of the seventh numerical embodiment.

TABLE 35 LENS SURFACE DATA Surf. No. R d N(d) ν(d)  1 67.355 2.5001.81600 46.6  2 27.200 0.280 1.52972 42.7  3* 23.051 8.470  4 62.3991.650 1.67790 55.3  5 31.542 9.360  6 −84.472 2.000 1.61800 63.4  745.529 5.190  8 52.133 9.020 1.56732 42.8  9 −114.250 d9  10 60.1753.410 1.72047 34.7 11 117.772 2.270 12 93.013 1.500 1.80000 29.9 1329.802 6.540 1.54814 45.8 14 −171.675 6.333 15 70.653 3.890 1.48749 70.216 −113.044 1.550 17 (Diaphragm) ∞ d17 18 −135.180 1.500 1.83400 37.2 1930.999 4.430 1.69895 30.1 20 −111.532 1.350 21 −161.160 1.500 1.8340037.2 22 105.416 0.850 23 81.455 2.050 1.80518 25.4 24 225.817 d24 2534.900 5.590 1.69680 55.5 26 −3000.000 1.500 1.75500 52.3 27 21.95011.980  1.49700 81.6 28 −52.568 0.750 29* −4804.554 0.200 1.52972 42.730 −4804.554 1.500 1.83400 37.2 31 36.559 7.270 1.48749 70.2 32 −105.169— The asterisk (*) designates an aspherical surface which isrotationally symmetrical with respect to the optical axis.

TABLE 36 ASPHERICAL SURFACE DATA Surf. No. K A4 A6 A8 A10 3 −1.0000.2577E−05 −0.4243E−09 0.7278E−12 −0.2727E−14 29 0.000 −0.3493E−050.1287E−08 −0.4405E−11 0.4233E−13

TABLE 37 VARIOUS LENS-SYSTEM DATA Zoom Ratio: 1.53 Short Focal LengthIntermediate Long Focal Length Extremity Focal Length Extremity FNO. 4.64.6 4.6 f 28.70 35.00 43.87 W 45.3 38.9 32.3 Y 27.80 27.80 27.80 fB66.85 74.86 84.74 L 224.70 220.21 219.82 d9 24.943 15.416 7.739 d174.760 9.800 17.090 d24 23.709 15.706 5.820

TABLE 38 LENS GROUP DATA Lens Group 1^(st) Surface Focal Length 1 1−29.38 2 10 53.37 3 18 −90.51 4 25 77.86

Numerical Embodiment 9

FIGS. 75 through 81C and Tables 39 through 42 show a ninth numericalembodiment of the zoom lens system according to the present invention.FIG. 75 shows a lens arrangement of the ninth numerical embodiment ofthe zoom lens system, at the short focal length extremity when focusedon an object at infinity. FIGS. 76A, 76B, 76C and 76D show variousaberrations that occurred in the lens arrangement shown in FIG. 75, atthe short focal length extremity when focused on an object at infinity.FIGS. 77A, 77B and 77C show lateral aberrations that occurred in thelens arrangement shown in FIG. 75, at the short focal length extremitywhen focused on an object at infinity. FIGS. 78A, 78B, 78C and 78D showvarious aberrations that occurred in the lens arrangement shown in FIG.75, at an intermediate focal length when focused on an object atinfinity. FIGS. 79A, 79B and 79C show lateral aberrations that occurredin the lens arrangement shown in FIG. 75, at an intermediate focallength when focused on an object at infinity. FIGS. 80A, 80B, 80C and80D show various aberrations that occurred in the lens arrangement shownin FIG. 75, at the long focal length extremity when focused on an objectat infinity. FIGS. 81A, 81B and 81C show lateral aberrations thatoccurred in the lens arrangement shown in FIG. 75, at the long focallength extremity when focused on an object at infinity. Table 39 showsthe lens surface data, Table 40 shows the aspherical surface data, Table41 shows various lens-system data, and Table 42 shows lens group data.

The fundamental lens arrangement of the ninth numerical embodiment isthe same as that of the seventh and eighth numerical embodiments exceptfor the following feature:

(1) In the third sub-lens group G4 a, the positive lens element 41 is aplanoconvex positive lens element having a convex surface on the objectside (a positive lens element having a convex surface on the objectside), and the negative lens element 42 is a planoconcave negative lenselement having a concave surface on the image side.

TABLE 39 LENS SURFACE DATA Surf. No. R d N (d) ν (d)  1 69.638 2.4101.77250 49.6  2 27.200 0.200 1.52972 42.7  3* 22.964 8.690  4 63.3831.650 1.72916 54.7  5 31.189 9.410  6 −91.673 2.200 1.61800 63.4  745.953 5.160  8 52.898 8.330 1.61340 44.3  9 −134.937  d9 10 57.2203.520 1.58144 40.7 11 185.088 2.300 12 136.444 1.500 1.80000 29.9 1328.661 6.670 1.59551 39.2 14 −171.854 6.401 15 72.184 3.830 1.49700 81.616 −115.495 1.570 17 (Diaphragm) ∞ d17 18 −91.231 1.500 1.81600 46.6 1935.110 4.540 1.65412 39.7 20 −71.436 1.040 21 −155.405 1.500 1.8340037.2 22 71.692 0.940 23 66.334 2.680 1.80518 25.4 24 418.671 d24 2534.105 5.650 1.80610 40.9 26 ∞ 1.500 1.83481 42.7 27 21.976 11.6101.49700 81.6 28 −55.278 0.960 29* −3249.477 0.200 1.52972 42.7 30−3249.477 1.760 1.83400 37.2 31 35.047 7.410 1.48749 70.2 32 −100.056 —The asterisk (*) designates an aspherical surface which is rotationallysymmetrical with respect to the optical axis.

TABLE 40 ASPHERICAL SURFACE DATA Surf. No. K A4 A6 A8 A10 3 −1.0000.2805E−05 −0.3972E−09 0.7407E−12 −0.2875E−14 29 0.000 −0.3223E−050.1193E−08 −0.2836E−11 0.3893E−13

TABLE 41 VARIOUS LENS-SYSTEM DATA Zoom Ratio: 1.53 Short Focal LengthIntermediate Long Focal Length Extremity Focal Length Extremity FNO. 4.64.6 4.6 f 28.70 35.00 43.87 W 45.3 38.9 32.3 Y 27.80 27.80 27.80 fB66.45 74.64 84.68 L 225.61 220.71 219.94 d9 24.966 15.369 7.671 d175.023 9.721 16.645 d24 24.042 15.855 5.816

TABLE 42 LENS GROUP DATA Lens Group 1^(st) Surface Focal Length 1 1−29.60 2 10 53.52 3 18 −91.20 4 25 78.43

Numerical Embodiment 10

FIGS. 82 through 88C and Tables 43 through 46 show a tenth numericalembodiment of the zoom lens system according to the present invention.FIG. 82 shows a lens arrangement of the tenth numerical embodiment ofthe zoom lens system, at the short focal length extremity when focusedon an object at infinity. FIGS. 83A, 83B, 83C and 83D show variousaberrations that occurred in the lens arrangement shown in FIG. 82, atthe short focal length extremity when focused on an object at infinity.FIGS. 84A, 84B and 84C show lateral aberrations that occurred in thelens arrangement shown in FIG. 82, at the short focal length extremitywhen focused on an object at infinity. FIGS. 85A, 85B, 85C and 85D showvarious aberrations that occurred in the lens arrangement shown in FIG.82, at an intermediate focal length when focused on an object atinfinity. FIGS. 86A, 86B and 86C show lateral aberrations that occurredin the lens arrangement shown in FIG. 82, at an intermediate focallength when focused on an object at infinity. FIGS. 87A, 87B, 87C and87D show various aberrations that occurred in the lens arrangement shownin FIG. 82, at the long focal length extremity when focused on an objectat infinity. FIGS. 88A, 88B and 88C show lateral aberrations thatoccurred in the lens arrangement shown in FIG. 82, at the long focallength extremity when focused on an object at infinity. Table 43 showsthe lens surface data, Table 44 shows the aspherical surface data, Table45 shows various lens-system data, and Table 46 shows lens group data.

The fundamental lens arrangement of the tenth numerical embodiment isthe same as that of the ninth numerical embodiment.

TABLE 43 LENS SURFACE DATA Surf. No. R d N (d) ν (d)  1 65.358 2.5301.81600 46.6  9 27.200 0.200 1.52972 42.7  3* 22.966 7.560  4 50.1091.650 1.77250 49.6  5 28.613 10.500  6 −79.656 2.500 1.64000 60.1  749.679 5.570  8 55.019 8.850 1.59551 39.2  9 −121.594  d9 10 63.1824.000 1.62588 35.7 11 157.222 2.670 12 97.531 1.730 1.80518 25.4 1328.966 6.850 1.60342 38.0 14 −134.949 5.847 15 82.219 3.430 1.49700 81.616 −165.107 1.730 17 (Diaphragm) ∞ d17 18 −87.197 1.500 1.83481 42.7 1938.016 4.540 1.63980 34.5 20 −65.237 0.800 21 −174.206 1.500 1.8010035.0 22 74.279 0.890 23 65.982 2.190 1.80518 25.4 24 229.516 d24 2533.851 5.650 1.80610 33.3 26 ∞ 1.500 1.83400 37.2 27 22.014 11.5201.49700 81.6 28 −58.817 0.750 29* −4773.318 0.200 1.52972 42.7 30−4773.318 1.500 1.83400 37.2 31 34.332 7.590 1.48749 70.2 32 −87.843 —The asterisk (*) designates an aspherical surface which is rotationallysymmetrical with respect to the optical axis.

TABLE 44 ASPHERICAL SURFACE DATA Surf. No. K A4 A6 A8 A10 3 −1.0000.2739E−05 −0.5024E−09 0.8817E−13 −0.2066E−14 29 0.000 −0.2973E−050.6725E−09 −0.1170E−11 0.3312E−13

TABLE 45 VARIOUS LENS-SYSTEM DATA Zoom Ratio: 1.54 Short Focal LengthIntermediate Long Focal Length Extremity Focal Length Extremity FNO. 4.64.6 4.6 f 28.70 35.00 44.06 W 45.3 38.9 32.3 Y 27.80 27.80 27.80 fB66.07 74.19 85.94 L 225.28 219.75 219.27 d9 23.647 14.287 6.365 d175.361 10.056 15.408 d24 24.461 15.465 5.816

TABLE 46 LENS GROUP DATA Lens Group 1^(st) Surface Focal Length 1 1−29.12 2 10 52.61 3 18 −87.85 4 25 77.37

Numerical Embodiment 11

FIGS. 89 through 95C and Tables 47 through 50 show an eleventh numericalembodiment of the zoom lens system according to the present invention.FIG. 89 shows a lens arrangement of the eleventh numerical embodiment ofthe zoom lens system, at the short focal length extremity when focusedon an object at infinity. FIGS. 90A, 90B, 90C and 90D show variousaberrations that occurred in the lens arrangement shown in FIG. 89, atthe short focal length extremity when focused on an object at infinity.FIGS. 91A, 91B and 91C show lateral aberrations that occurred in thelens arrangement shown in FIG. 89, at the short focal length extremitywhen focused on an object at infinity. FIGS. 92A, 92B, 92C and 92D showvarious aberrations that occurred in the lens arrangement shown in FIG.89, at an intermediate focal length when focused on an object atinfinity. FIGS. 93A, 93B and 93C show lateral aberrations that occurredin the lens arrangement shown in FIG. 89, at an intermediate focallength when focused on an object at infinity. FIGS. 94A, 94B, 94C and94D show various aberrations that occurred in the lens arrangement shownin FIG. 89, at the long focal length extremity when focused on an objectat infinity. FIGS. 95A, 95B and 95C show lateral aberrations thatoccurred in the lens arrangement shown in FIG. 89, at the long focallength extremity when focused on an object at infinity. Table 47 showsthe lens surface data, Table 48 shows the aspherical surface data, Table49 shows various lens-system data, and Table 50 shows lens group data.

The fundamental lens arrangement of the eleventh numerical embodiment isthe same as that of the seventh and eighth numerical embodiments.

TABLE 47 LENS SURFACE DATA Surf. No. R d N (d) ν (d)  1 64.035 2.0501.81600 46.6  2 27.200 0.200 1.52972 42.7  3* 22.725 7.810  4 50.3491.690 1.69680 55.5  5 28.771 10.290  6 −75.682 2.000 1.61800 63.4  747.104 6.030  8 55.387 8.410 1.56732 42.8  9 −115.424  d9 10 64.9533.020 1.72825 28.5 11 137.231 2.450 12 125.689 1.500 1.80518 25.4 1329.943 6.550 1.59270 35.3 14 −157.141 6.380 15 63.925 3.940 1.49700 81.616 −126.239 1.630 17 (Diaphragm) ∞ d17 18 −81.989 1.500 1.83481 42.7 1935.152 4.870 1.63980 34.5 20 −56.288 0.730 21 −173.240 1.500 1.8010035.0 22 73.769 0.870 23 63.476 2.400 1.69895 30.1 24 317.385 d24 2535.772 6.550 1.65160 58.5 26 −2500.000 1.530 1.72916 54.7 27 21.95012.150 1.49700 81.6 28 −50.109 0.750 29* −4801.325 0.300 1.52972 42.7 30−4801.325 1.590 1.83400 37.2 31 40.334 6.600 1.48749 70.2 32 −143.721 —The asterisk (*) designates an aspherical surface which is rotationallysymmetrical with respect to the optical axis.

TABLE 48 ASPHERICAL SURFACE DATA Surf. No. K A4 A6 A8 A10 3 −1.0000.2545E−05 −0.3779E−09 −0.1557E−12 −0.2334E−14 29 0.000 −0.3479E−050.1487E−08 −0.6826E−11 0.4835E−13

TABLE 49 VARIOUS LENS-SYSTEM DATA Zoom Ratio: 1.53 Short Focal LengthIntermediate Long Focal Length Extremity Focal Length Extremity FNO. 4.64.6 4.6 f 28.70 35.00 43.87 W 45.3 39.0 32.4 Y 27.80 27.80 27.80 fB67.50 76.44 87.16 L 226.00 220.46 219.14 d9 22.663 12.979 5.314 d175.070 9.214 15.555 d24 25.477 16.534 5.820

TABLE 50 LENS GROUP DATA Lens Group 1^(st) Surface Focal Length 1 1−29.01 2 10 52.54 3 18 −93.22 4 25 80.73

Numerical Embodiment 12

FIGS. 96 through 102C and Tables 51 through 54 show a twelfth numericalembodiment of the zoom lens system according to the present invention.FIG. 96 shows a lens arrangement of the twelfth numerical embodiment ofthe zoom lens system, at the short focal length extremity when focusedon an object at infinity. FIGS. 97A, 97B, 97C and 97D show variousaberrations that occurred in the lens arrangement shown in FIG. 96, atthe short focal length extremity when focused on an object at infinity.FIGS. 98A, 98B and 98C show lateral aberrations that occurred in thelens arrangement shown in FIG. 96, at the short focal length extremitywhen focused on an object at infinity. FIGS. 99A, 99B, 99C and 99D showvarious aberrations that occurred in the lens arrangement shown in FIG.96, at an intermediate focal length when focused on an object atinfinity. FIGS. 100A, 100B and 100C show lateral aberrations thatoccurred in the lens arrangement shown in FIG. 96, at an intermediatefocal length when focused on an object at infinity. FIGS. 101A, 101B,101C and 101D show various aberrations that occurred in the lensarrangement shown in FIG. 96, at the long focal length extremity whenfocused on an object at infinity. FIGS. 102A, 102B and 102C show lateralaberrations that occurred in the lens arrangement shown in FIG. 96, atthe long focal length extremity when focused on an object at infinity.Table 51 shows the lens surface data, Table 52 shows the asphericalsurface data, Table 53 shows various lens-system data, and Table 54shows lens group data.

The fundamental lens arrangement of the twelfth numerical embodiment isthe same as that of the seventh and eighth numerical embodiments exceptfor the following features:

(1) In the third sub-lens group G4 a, the positive lens element 41 is aplanoconvex positive lens element having a convex surface on the objectside (a positive lens element having a convex surface on the objectside), and the negative lens element 42 is a planoconcave negative lenselement having a concave surface on the image side.

(2) In the fourth sub-lens group G4 b, the negative lens element 44 is anegative meniscus lens element having a convex surface on the objectside. The negative meniscus lens element 44 is a hybrid lens formed by aglass lens element with an aspherical surface layer, formed from asynthetic resin material, adhered onto the object side thereof.

TABLE 51 LENS SURFACE DATA Surf. No. R d N (d) ν (d)  1 65.300 2.0501.81600 46.6  2 27.500 0.200 1.52972 42.7  3* 23.026 7.580  4 50.0321.650 1.72916 54.7  5 27.123 9.230  6 −119.300 2.000 1.72916 54.7  758.906 5.650  8 62.025 7.430 1.72047 34.7  9 −247.562  d9 10 74.6353.800 1.61340 44.3 11 803.387 2.070 12 129.693 1.500 1.80000 29.9 1328.740 6.080 1.60342 38.0 14 −678.444 6.519 15 59.735 3.830 1.48749 70.216 −95.576 1.580 17 (Diaphragm) ∞ d17 18 −79.495 1.500 1.83481 42.7 1933.950 4.950 1.65412 39.7 20 −56.518 0.980 21 −254.800 1.500 1.8340037.2 22 56.444 1.030 23 53.174 2.520 1.80518 25.4 24 209.861 d24 2533.840 6.000 1.61800 63.4 26 ∞ 1.500 1.72916 54.7 97 21.950 12.1601.49700 81.6 28 −54.079 0.750 29* 198.653 0.270 1.52972 42.7 30 198.6532.100 1.83400 37.2 31 34.541 6.330 1.48749 70.2 32 −1261.416 — Theasterisk (*) designates an aspherical surface which is rotationallysymmetrical with respect to the optical axis.

TABLE 52 ASPHERICAL SURFACE DATA Surf. No. K A4 A6 A8 A10 3 −1.0000.2736E−05 −0.1235E−08 0.2360E−12 −0.2427E−14 29 0.000 −0.3584E−050.2059E−08 −0.1162E−10 0.4874E−13

TABLE 53 VARIOUS LENS-SYSTEM DATA Zoom Ratio: 1.53 Short Focal LengthIntermediate Long Focal Length Extremity Focal Length Extremity FNO. 4.64.6 4.6 f 28.70 34.99 43.87 W 45.3 39.0 32.5 Y 27.80 27.80 27.80 fB66.01 74.88 85.57 L 226.55 220.92 219.35 d9 27.248 17.502 9.675 d175.110 9.233 15.476 d24 25.420 16.550 5.870

TABLE 54 LENS GROUP DATA Lens Group 1^(st) Surface Focal Length 1 1−28.86 2 10 52.18 3 18 −94.52 4 25 83.11

Numerical Embodiment 13

FIGS. 103 through 109C and Tables 55 through 58 show a thirteenthnumerical embodiment of the zoom lens system according to the presentinvention. FIG. 103 shows a lens arrangement of the thirteenth numericalembodiment of the zoom lens system, at the short focal length extremitywhen focused on an object at infinity. FIGS. 104A, 104B, 104C and 104Dshow various aberrations that occurred in the lens arrangement shown inFIG. 103, at the short focal length extremity when focused on an objectat infinity. FIGS. 105A, 105B and 105C show lateral aberrations thatoccurred in the lens arrangement shown in FIG. 103, at the short focallength extremity when focused on an object at infinity. FIGS. 106A,106B, 106C and 106D show various aberrations that occurred in the lensarrangement shown in FIG. 103, at an intermediate focal length whenfocused on an object at infinity. FIGS. 107A, 107B and 107C show lateralaberrations that occurred in the lens arrangement shown in FIG. 103, atan intermediate focal length when focused on an object at infinity.FIGS. 108A, 108B, 108C and 108D show various aberrations that occurredin the lens arrangement shown in FIG. 103, at the long focal lengthextremity when focused on an object at infinity. FIGS. 109A, 109B and109C show lateral aberrations that occurred in the lens arrangementshown in FIG. 103, at the long focal length extremity when focused on anobject at infinity. Table 55 shows the lens surface data, Table 56 showsthe aspherical surface data, Table 57 shows various lens-system data,and Table 58 shows lens group data.

The fundamental lens arrangement of the thirteenth numerical embodimentis the same as that of the ninth and tenth numerical embodiments.

TABLE 55 LENS SURFACE DATA Surf. No. R d N (d) ν (d)  1 61.215 2.0501.80400 46.6  2 27.200 0.200 1.52972 42.7  3* 22.791 7.420  4 48.6041.650 1.75500 52.3  5 26.347 10.510  6 −78.561 1.800 1.61800 63.4  749.100 6.050  8 55.131 8.670 1.60562 43.7  9 −129.547 d9 10 55.088 4.3601.54072 47.2 11 234.815 2.150 12 135.804 1.500 1.80000 29.9 13 28.4637.030 1.59551 39.2 14 −139.912 6.058 15 70.833 3.730 1.49700 81.6 16−141.899 1.710 17 (Diaphragm) ∞ d17 18 −93.730 1.500 1.83481 42.7 1937.144 4.690 1.58144 40.7 20 −59.430 0.800 21 −168.561 1.500 1.8348142.7 22 62.147 0.940 23 59.027 2.500 1.80518 25.4 24 405.068 d24 2534.602 6.820 1.80518 25.4 26 ∞ 1.500 1.80000 29.9 27 21.950 11.4401.49700 81.6 28 −61.136 0.800 29* −3333.333 0.200 1.52972 42.7 30−3333.333 1.500 1.80100 35.0 31 32.929 7.590 1.48749 70.2 32 −98.355 —The asterisk (*) designates an aspherical surface which is rotationallysymmetrical with respect to the optical axis.

TABLE 56 ASPHERICAL SURFACE DATA Surf. No. K A4 A6 A8 A10 3 −1.0000.2883E−05 −0.8451E−09 −0.3721E−12 −0.2515E−14 29 0.000 −0.3131E−05−0.4836E−09 0.2992E−11 0.1824E−13

TABLE 57 VARIOUS LENS-SYSTEM DATA Zoom Ratio: 1.53 Short Focal LengthIntermediate Long Focal Length Extremity Focal Length Extremity FNO. 4.64.6 4.6 f 28.70 35.00 43.87 W 45.3 39.0 32.5 Y 27.80 27.80 27.80 fB67.22 76.18 86.57 L 225.43 219.73 218.29 d9 21.417 12.373 5.438 d174.960 8.299 13.793 d24 25.165 16.210 5.816

TABLE 58 LENS GROUP DATA Lens Group 1^(st) Surface Focal Length 1 1−29.21 2 10 52.18 3 18 −80.91 4 25 73.91

Numerical Embodiment 14

FIGS. 110 through 116C and Tables 59 through 62 show a fourteenthnumerical embodiment of the zoom lens system according to the presentinvention. FIG. 110 shows a lens arrangement of the fourteenth numericalembodiment of the zoom lens system, at the short focal length extremitywhen focused on an object at infinity. FIGS. 111A, 111B, 111C and 111Dshow various aberrations that occurred in the lens arrangement shown inFIG. 110, at the short focal length extremity when focused on an objectat infinity. FIGS. 112A, 112B and 112C show lateral aberrations thatoccurred in the lens arrangement shown in FIG. 110, at the short focallength extremity when focused on an object at infinity. FIGS. 113A,113B, 113C and 113D show various aberrations that occurred in the lensarrangement shown in FIG. 110, at an intermediate focal length whenfocused on an object at infinity. FIGS. 114A, 114B and 114C show lateralaberrations that occurred in the lens arrangement shown in FIG. 110, atan intermediate focal length when focused on an object at infinity.FIGS. 115A, 115B, 115C and 115D show various aberrations that occurredin the lens arrangement shown in FIG. 110, at the long focal lengthextremity when focused on an object at infinity. FIGS. 116A, 116B and116C show lateral aberrations that occurred in the lens arrangementshown in FIG. 110, at the long focal length extremity when focused on anobject at infinity. Table 59 shows the lens surface data, Table 60 showsthe aspherical surface data, Table 61 shows various lens-system data,and Table 62 shows lens group data.

The fundamental lens arrangement of the fourteenth numerical embodimentis the same as that of the ninth, tenth and thirteenth numericalembodiments.

TABLE 59 LENS SURFACE DATA Surf. No. R d N (d) ν (d)  1 62.732 2.0601.79952 42.2  2 27.200 0.200 1.52972 42.7  3* 22.431 7.590  4 44.3931.650 1.81600 46.6  5 25.367 13.400  6 −86.316 2.000 1.67790 55.3  753.947 4.950  8 55.435 7.130 1.63980 34.5  9 −149.495 d9 10 83.857 3.2001.67270 32.1 11 327.659 1.100 12 69.229 2.290 1.80518 25.4 13 28.1687.590 1.58144 40.7 14 −184.840 5.270 15 84.318 3.780 1.49700 81.6 16−141.779 1.710 17 (Diaphragm) ∞ d17 18 −187.069 1.500 1.83481 42.7 1934.987 4.610 1.53172 48.9 20 −76.198 0.800 21 −168.600 1.500 1.8348142.7 22 54.034 0.970 23 53.321 2.430 1.80518 25.4 24 545.285 d24 2534.169 5.590 1.80000 29.9 26 ∞ 1.500 1.80100 35.0 27 22.167 11.1801.49700 81.6 28 −70.031 0.750 29* −3178.150 0.300 1.52972 42.7 30−3178.150 2.610 1.83400 37.2 31 31.757 8.180 1.49700 81.6 32 −76.901 —The asterisk (*) designates an aspherical surface which is rotationallysymmetrical with respect to the optical axis.

TABLE 60 ASPHERICAL SURFACE DATA Surf. No. K A4 A6 A8 A10 3 −1.0000.2715E−05 −0.1463E−08 −0.5046E−12 −0.3263E−14 29 0.000 −0.2635E−050.3314E−09 −0.1586E−12 0.2446E−13

TABLE 61 VARIOUS LENS-SYSTEM DATA Zoom Ratio: 1.53 Short Focal LengthIntermediate Long Focal Length Extremity Focal Length Extremity FNO. 4.64.6 4.6 f 28.70 35.00 43.87 W 44.8 38.8 32.4 Y 27.80 27.80 27.80 fB65.85 74.57 87.31 L 225.83 219.02 218.63 d9 22.758 14.335 7.301 d174.900 8.723 12.368 d24 26.474 15.558 5.816

TABLE 62 LENS GROUP DATA Lens Group 1^(st) Surface Focal Length 1 1−27.09 2 10 49.01 3 18 −79.02 4 25 76.59

Numerical Embodiment 15

FIGS. 117 through 123C and Tables 63 through 66 show a fifteenthnumerical embodiment of the zoom lens system according to the presentinvention. FIG. 117 shows a lens arrangement of the fifteenth numericalembodiment of the zoom lens system, at the short focal length extremitywhen focused on an object at infinity. FIGS. 118A, 118B, 118C and 118Dshow various aberrations that occurred in the lens arrangement shown inFIG. 117, at the short focal length extremity when focused on an objectat infinity. FIGS. 119A, 119B and 119C show lateral aberrations thatoccurred in the lens arrangement shown in FIG. 117, at the short focallength extremity when focused on an object at infinity. FIGS. 120A,120B, 120C and 120D show various aberrations that occurred in the lensarrangement shown in FIG. 117, at an intermediate focal length whenfocused on an object at infinity. FIGS. 121A, 121B and 121C show lateralaberrations that occurred in the lens arrangement shown in FIG. 117, atan intermediate focal length when focused on an object at infinity.FIGS. 122A, 122B, 122C and 122D show various aberrations that occurredin the lens arrangement shown in FIG. 117, at the long focal lengthextremity when focused on an object at infinity. FIGS. 123A, 123B and123C show lateral aberrations that occurred in the lens arrangementshown in FIG. 117, at the long focal length extremity when focused on anobject at infinity. Table 63 shows the lens surface data, Table 64 showsthe aspherical surface data, Table 65 shows various lens-system data,and Table 66 shows lens group data.

The fundamental lens arrangement of the fifteenth numerical embodimentis the same as that of the ninth, tenth, thirteenth and fourteenthnumerical embodiments.

TABLE 63 LENS SURFACE DATA Surf. No. R d N (d) ν (d)  1 61.615 2.0501.79952 42.2  2 27.200 0.200 1.52972 42.7  3* 22.385 7.820  4 43.6801.650 1.80440 39.6  5 24.960 13.450  6 −86.610 2.200 1.67790 55.3  751.905 4.790  8 54.398 7.390 1.66680 33.0  9 −177.664 d9 10 84.841 3.2001.72151 29.2 11 314.128 1.550 12 65.840 1.500 1.80518 25.4 13 27.5317.410 1.58144 40.7 14 −201.077 5.166 15 83.879 3.580 1.49700 81.6 16−148.056 1.720 17 (Diaphragm) ∞ d17 18 −523.319 1.500 1.83481 42.7 1932.613 4.600 1.51742 52.4 20 −90.712 0.700 21 −151.265 1.500 1.8348142.7 22 51.464 0.960 23 50.433 2.530 1.78472 25.7 24 607.345 d24 2533.569 5.650 1.80000 29.9 26 ∞ 1.500 1.80100 35.0 27 21.950 11.3201.49700 81.6 28 −78.126 0.810 29* −2089.969 0.200 1.52972 42.7 30−2089.969 2.230 1.83400 37.2 31 31.062 8.500 1.49700 81.6 32 −67.070 —The asterisk (*) designates an aspherical surface which is rotationallysymmetrical with respect to the optical axis.

TABLE 64 ASPHERICAL SURFACE DATA Surf. No. K A4 A6 A8 A10 3 −1.0000.2709E−05 −0.1514E−08 −0.6028E−12 −0.3340E−14 29 0.000 −0.2632E−050.4566E−09 0.3709E−12 0.2249E−13

TABLE 65 VARIOUS LENS-SYSTEM DATA Zoom Ratio: 1.53 Short Focal LengthIntermediate Long Focal Length Extremity Focal Length Extremity FNO. 4.64.6 4.6 f 28.70 35.00 43.87 W 44.6 38.7 32.4 Y 27.80 27.80 27.80 fB65.85 74.81 87.85 L 224.85 217.85 217.68 d9 22.070 13.879 7.038 d174.470 8.004 11.297 d24 26.778 15.481 5.820

TABLE 66 LENS GROUP DATA Lens Group 1^(st) Surface Focal Length 1 1−26.74 2 10 48.34 3 18 −77.81 4 25 75.96

The numerical values of each condition for each of the first throughsixth embodiments are shown in Table 67.

TABLE 67 Embod. 1 Embod. 2 Embod. 3 Cond. (1) 0.11 0.40 0.55 Cond. (2)−0.09 −0.05 −0.14 Cond. (3) 0.11 −0.81 −1.06 Cond. (4) −0.51 −0.36 −0.34Cond. (5) −0.62 −0.44 −0.41 Embod. 4 Embod. 5 Embod. 6 Cond. (1) 0.810.92 1.07 Cond. (2) 0.28 0.11 −0.60 Cond. (3) −0.26 −0.41 0.68 Cond. (4)−0.64 −0.55 −0.29 Cond. (5) −0.78 −0.67 −0.35

As can be understood from Table 67, the first through sixth numericalembodiments satisfy conditions (1) through (5). Furthermore, as can beunderstood from the aberration diagrams, the various aberrations arefavorably corrected.

The numerical values of each condition for each of the seventh throughfifteenth embodiments are shown in Table 68.

TABLE 68 Embod. 7 Embod. 8 Embod. 9 Cond. (6) 1.388 1.451 1.568 Cond.(7) −1.79 −1.82 −1.81 Cond. (8) 2.80 3.08 3.08 Cond. (9) −2.42 −2.65−2.65 Cond. (10) −0.90 −0.92 −0.91 Cond. (11) −1.99 −1.97 −1.93 Cond.(12) 19.8 16.2 18.5 Cond. (13) 7.5 13.4 12.4 Cond. (14) 4.91 6.11 5.92Cond. (15) 0.573 0.573 0.563 Embod. 10 Embod. 11 Embod. 12 Cond. (6)1.763 1.875 1.886 Cond. (7) −1.81 −1.81 −1.81 Cond. (8) 3.02 3.21 3.28Cond. (9) −2.66 −2.78 −2.88 Cond. (10) −0.98 −0.94 −0.89 Cond. (11)−2.22 −1.97 −1.79 Cond. (12) 20.3 15.4 17.8 Cond. (13) 12.1 17.5 32.0Cond. (14) 5.47 6.31 6.96 Cond. (15) 0.580 0.573 0.583 Embod. 13 Embod.14 Embod. 15 Cond. (6) 2.191 2.596 2.797 Cond. (7) −1.79 −1.81 −1.81Cond. (8) 2.77 2.92 2.91 Cond. (9) −2.53 −2.83 −2.84 Cond. (10) −0.95−1.12 −1.16 Cond. (11) −2.10 −2.58 −2.66 Cond. (12) 23.7 20.7 20.7 Cond.(13) 6.6 9.7 9.3 Cond. (14) 4.24 4.58 4.44 Cond. (15) 0.572 0.592 0.596

As can be understood from Table 68, the seventh through fifteenthnumerical embodiments satisfy conditions (6) through (15). Furthermore,as can be understood from the aberration diagrams, the variousaberrations are favorably corrected.

Even if a lens element or lens group having effectively no refractivepower were to be added to the zoom lens system included in the scope ofthe claims of the present invention, such a zoom lens system would stillremain within the technical scope of the present invention (and wouldnot be excluded from the technical scope of the present invention).

Obvious changes may be made in the specific embodiments of the presentinvention described herein, such modifications being within the spiritand scope of the invention claimed. It is indicated that all mattercontained herein is illustrative and does not limit the scope of thepresent invention.

What is claimed is:
 1. A zoom lens system comprising a negative firstlens group, a positive second lens group, a negative third lens groupand a positive fourth lens group, in that order from the object side,wherein upon zooming from a short focal length extremity to a long focallength extremity, at least said first lens group, said second lens groupand said fourth lens group are moved in the optical axis direction ofthe zoom lens system, wherein said third lens group includes a negativefirst sub-lens group and a negative second sub-lens group, in that orderfrom the object side, and wherein said second sub-lens group is providedwith a negative single lens element and a positive single lens element,and an air lens is formed between said negative single lens element andsaid positive single lens element.
 2. The zoom lens system according toclaim 1, wherein said second sub-lens group comprises a negative singlelens element having a concave surface on the image side, and a positivesingle lens element having a convex surface on the object side, in thatorder from the object side, wherein a meniscus shaped air lens having aconvex surface on the object side is formed between said negative singlelens element and said positive single lens element.
 3. The zoom lenssystem according to claim 1, wherein the following relationship issatisfied:0.1<Ri/Ro<1.1 wherein Ri designates a radius of curvature of a surfaceon the image side of said air lens provided within said second sub-lensgroup, and Ro designates a radius of curvature of a surface on theobject side of said air lens provided within said second sub-lens group.4. The zoom lens system according to claim 2, wherein the followingrelationship is satisfied:0.1<Ri/Ro<1.1 wherein Ri designates a radius of curvature of a surfaceon the image side of said air lens provided within said second sub-lensgroup, and Ro designates a radius of curvature of a surface on theobject side of said air lens provided within said second sub-lens group.5. The zoom lens system according to claim 1, wherein the focal lengthof said air lens provided within said second sub-lens group has apositive value.
 6. The zoom lens system according to claim 1, whereinthe following relationship is satisfied:−0.7<(R3ao+R3ai)/(R3ao−R3ai)<0.3 wherein R3ao designates a radius ofcurvature of a surface on the object side of said first sub-lens group,and R3ai designates a radius of curvature of a surface on the image sideof said first sub-lens group.
 7. The zoom lens system according to claim1, wherein the following relationship is satisfied:−1.1<(R3ai+R3bo)/(R3ai−R3bo)<0.7 wherein R3ai designates a radius ofcurvature of a surface on the image side of said first sub-lens group,and R3bo designates a radius of curvature of a surface on the objectside of said second sub-lens group.
 8. The zoom lens system according toclaim 1, wherein the following relationships are satisfied:−0.7<(1−m3bS)·m4S<−0.2and−0.8<(1−m3bL)·m4L<−0.3 wherein m3bS designates a lateral magnificationof said second sub-lens group when focusing on an object at infinity atthe short focal length extremity, m4S designates a lateral magnificationof said fourth lens group when focusing on an object at infinity at theshort focal length extremity, m3bL designates a lateral magnification ofsaid second sub-lens group when focusing on an object at infinity at thelong focal length extremity, and m4L designates a lateral magnificationof said fourth lens group when focusing on an object at infinity at thelong focal length extremity.
 9. The zoom lens system according to claim1, wherein upon zooming from the short focal length extremity to thelong focal length extremity, said third lens group remains stationarywith respect to the optical axis direction.
 10. The zoom lens systemaccording to claim 1, wherein upon zooming from the short focal lengthextremity to the long focal length extremity, said third lens groupmoves in the optical axis direction.